Thermoplastic elastomers via reversible addition-fragmentation chain transfer polymerization of triglycerides

ABSTRACT

The present invention relates to a thermoplastic block copolymer comprising at least one PA block and at least one PB block. The PA block represents a polymer block comprising one or more units of monomer A, and the PB block represents a polymer block comprising one or more units of monomer B. Monomer A is a vinyl, acrylic, diolefin, nitrile, dinitrile, acrylonitrile monomer, a monomer with reactive functionality, or a crosslinking monomer. Monomer B is a radically polymerizable triglyceride or mixtures thereof, typically in the form of a plant or animal oil. The present invention also relates to a method of preparing a thermoplastic block copolymer or novel thermoplastic statistical copolymers by polymerizing a radically polymerizable monomer with a radically polymerizable triglyceride or mixtures thereof via reversible addition-fragmentation chain-transfer polymerization (RAFT), in the presence of an free radical initiator and a chain transfer agent.

This application is a divisional application of U.S. patent applicationSer. No. 15/487,570 filed Apr. 14, 2017, which is a divisionalapplication of U.S. patent application Ser. No. 14/282,737, filed May20, 2014, now U.S. Pat. No. 9,650,463, issued May 16, 2017, which claimsthe priority benefit of U.S. Provisional Patent Application Ser. No.61/825,241, filed May 20, 2013, which is hereby incorporated byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a novel thermoplastic elastomercomposition and methods of making and using them in variousapplications. In particular, the present invention relates to successfulapplication of reversible addition-fragmentation chain transferpolymerization (RAFT) for making novel thermoplastic homopolymers,thermoplastic elastomeric block copolymers, and thermoplasticelastomeric statistical copolymers. These polymers are derived from atleast one radically polymerizable triglyceride or mixture oftriglycerides, typically in the form of a plant oil, animal oil, orsynthetic triglycerides. The thermoplastic copolymers additionallyinclude at least one radically polymerizable monomer.

BACKGROUND OF THE INVENTION

Styrenic block copolymers (SBCs), most notably those of DuPont's Kraton®family, such as styrene-butadiene type polymers (e.g., styrene-butadienedi-block, SB; styrene-butadiene-styrene tri-block, SBS), havehistorically served the asphalt and footwear industries for years, withmarkets also in the industries of packaging, pressure sensitiveadhesives, packaging materials, etc. Of these markets, the use of SBSsas bitumen modifiers is one of the largest and the most forgiving interms of material properties.

The global asphalt market is to reach 118.4 million metric tons by 2015,according to a January 2011 report by Global Industry Analysts, Inc. Theasphalt paving industry accounts for the largest end-use market segmentof asphalt. With increasing growth in the developing markets of China,India, and Eastern Europe, asphalt will be increasingly needed toconstruct roadway infrastructure for the next decade. The increaseddemand for asphalt, along with the need for improved asphaltmaterials/pavement performance, creates the opportunity for an asphaltmodifier.

The grade of the asphalt governs the performance of paving mixtures atin-service temperatures. In many cases, the characteristics of bitumenneeds to be altered to improve its elastic recovery/ductility at lowtemperatures for sufficient cracking resistance as well as to increaseits shearing resistance for sustained loads and/or at high temperaturesfor rutting resistance. The physical properties of bitumen are typicallymodified with the addition of SBS polymers to produce an improvedasphalt grade that enhances the performance of asphalt paving mixtures.Of the asphalt mixtures that are polymer modified, approximately 80% ofpolymer modified asphalt uses SBS-type polymers.

Over the past few years, the price of butadiene, the principal componentof SBC polymers used for bitumen modification, has increaseddramatically. In 2008, there was a shortage of SBS polymers for theasphalt industry. With the forecast of increasing demand of liquidasphalt for the next decade, there remains a strong need for a new typeof cost-effective, environment-friendly, viable polymers that can beused as an asphalt modifier in lieu of standard styrene-butadiene typemodifiers.

Vegetable oils have been considered as monomeric feedstocks for theplastics industry for over 20 years. Polymers from vegetable oils haveobtained increasing attention as public policy makers and corporationsalike have been interested in replacing traditional petrochemicalfeedstocks due to their environmental and economic impact.

To date, moderate success has been achieved through the application oftraditional cationic and free radical polymerization routes to vegetableoils to yield thermoset plastics (i.e., plastics which, oncesynthesized, permanently retain their shape and are not subject tofurther processing). For example, a variety of polymers, ranging fromsoft rubbers to hard, tough plastics were made by using cationiccopolymerization of vegetable oils, mainly soybean oil (SBO), usingboron triflouridediethyletherate (BFE) as initiator (Andjelkovic et al.,“Novel Polymeric Materials from Soybean Oils: Synthesis, Properties, andPotential Applications,” ACS Symposium Series, 921: 67-81 (2006); Daniel& Larock, “Thermophysical properties of conjugated soybean oil/cornstover biocomposites.” Bioresource Technology 101(15):6200-06 (2010)).Soybean-oil-based waterborne polyurethane films were synthesized withdifferent properties ranging from elastomeric polymers to rigid plasticsby changing the polyol functionality and hard segment content of thepolymers (Lu et al., “New Sheet Molding Compound Resins From SoybeanOil. I. Synthesis and Characterization,” Polymer 46(1):71-80 (2005); Luet al., “Surfactant-Free Core-Shell Hybrid Latexes From SoybeanOil-Based Waterborne Polyurethanes and Poly(Styrene-Butyl Acrylate),”Progress in Organic Coatings 71(4):336-42 (2011)). Moreover, soybean oilwas used to synthesize different bio-based products such as sheetmolding composites, elastomers, coatings, foams, etc. (Zhu et al.,“Nanoclay Reinforced Bio-Based Elastomers: Synthesis andCharacterization,” Polymer 47(24):8106-15 (2006)). Bunker et al. (Bunkeret al., “Miniemulsion Polymerization of Acrylated Methyl Oleate forPressure Sensitive Adhesives,” International Journal of Adhesion andAdhesives 23(1):29-38 (2003); Bunker et al., “Synthesis andCharacterization of Monomers and Polymers for Adhesives from MethylOleate,” Journal of Polymer Science Part A: Polymer Chemistry40(4):451-58 (2002)) synthesized pressure sensitive adhesives usingmini-emulsion polymerization of acrylatedmethyloleate, a monoglyceridederived from soy bean oil; the polymers produced were comparable totheir petroleum counterparts. Zhu et al., “Nanoclay Reinforced Bio-BasedElastomers: Synthesis and Characterization,” Polymer 47(24):8106-15(2006), generated an elastic network based on acrylated oleic methylester through bulk polymerization using ethylene glycol as thecrosslinker, obtaining a high molecular weight linear polymer usingmini-emulsion polymerization. Lu et al., “New Sheet Molding CompoundResins From Soybean Oil. I. Synthesis and Characterization,” Polymer46(1):71-80 (2005), created thermosetting resins synthesized fromsoybean oil that can be used in sheet molding compound applications byintroducing acid functionality onto the soybean and reacting the acidgroups with divalent metallic oxides or hydroxides, forming the sheet.Bonnaillie et al., “Thermosetting Foam With a High Bio-Based ContentFrom Acrylated Epoxidized Soybean Oil and Carbon Dioxide,” Journal ofApplied Polymer Science 105(3):1042-52 (2007), created a thermosettingfoam system using a pressurized carbon dioxide foaming process ofacrylated epoxidized soybean oil (AESO). U.S. Pat. No. 6,121,398 to Khotet al., synthesized liquid molding resins that are able to cure intohigh modulus thermosetting polymers and composites using triglyceridesderived from plant oils.

However, uncontrolled chain branching and crosslinking is inevitable byusing these conventional polymerization routes due to themultifunctional nature of triglycerides, multiple initiation sites alongthe chain backbone, and chain transfer/termination reactions. Whilethese thermoset materials may indeed supplant a number ofpetrochemically-derived thermosets, the vast majority of commoditypolymers are highly processable thermoplastic materials. There is thus aneed in the art to develop from vegetable oils a highly processablethermoplastic and elastomeric polymer with a wide range of applicationsand physical properties.

The present invention is directed to fulfilling these needs in the art.

SUMMARY OF THE INVENTION

One aspect of the present invention relates to a thermoplastic blockcopolymer comprising at least one PA block and at least one PB block.The PA block represents a polymer block comprising one or more units ofmonomer A, and the PB block represents a polymer block comprising one ormore units of monomer B. Monomer A is a vinyl, acrylic, diolefin,nitrile, dinitrile, acrylonitrile monomer, a monomer with reactivefunctionality, or a crosslinking monomer. Monomer B is a radicallypolymerizable triglyceride or mixture thereof, in the form of a plantoil, animal oil, or synthetic triglycerides. One end or both ends of thePA block or PB block in the thermoplastic block copolymer isfunctionalized with a thiocarbonylthio chain transfer group.

Another aspect of the present invention relates to a telechelicthermoplastic block copolymer having an architecture of(PA-PB)_(n)-TCTA-(PB-PA)_(n) or (PB-PA)_(n)-TCTA-(PA-PB)_(n), where n isan integer ranging from 1 to 10. TCTA is a moiety in the PB block or PAblock from a telechelic chain transfer agent used to produce thetelechelic thermoplastic block copolymer. The PA block represents apolymer block comprising one or more units of monomer A, and the PBblock represents a polymer block comprising one or more units of monomerB. Monomer A is a vinyl, acrylic, diolefin, nitrile, dinitrile,acrylonitrile monomer, a monomer with reactive functionality, or acrosslinking monomer. Monomer B is a radically polymerizabletriglyceride or mixtures thereof, in the form of a plant oil, animaloil, or synthetic triglycerides.

Another aspect of the present invention relates to a thermoplasticstatistical copolymer having a general formula of[A_(i)-B_(j)-C_(k)]_(q). In the formula, A represents monomer A, whichis a vinyl, acrylic, diolefin, nitrile, dinitrile, acrylonitrilemonomer, a monomer with reactive functionality, or a crosslinkingmonomer. B represents monomer B, which is a radically polymerizabletriglyceride or mixture thereof, in the form of a plant oil, animal oil,or synthetic triglycerides. C represents monomer C, which is a vinyl,acrylic, diolefin, nitrile, dinitrile, acrylonitrile monomer, a monomerwith reactive functionality, or a crosslinking monomer; or a radicallypolymerizable triglyceride or mixture thereof, in the form of a plantoil, animal oil, or synthetic triglycerides, provided monomer C isdifferent than the monomer A or monomer B. i, j, and k are averagenumber of repeating units of monomer A, monomer B, and monomer C,respectively, such that i and j are each greater than 0 and less than 1,k is 0 to less than 1, provided i+j+k=1. q represents the number averagedegree of polymerization and ranges from 10 to 100,000.

One aspect of the present invention also relates to a method ofpreparing a thermoplastic block copolymer. The method comprisesproviding a radically polymerizable monomer, represented by A, or apolymer block PA comprising one or more units of monomer A. A radicallypolymerizable triglyceride or mixture thereof, in the form of a plantoil, animal oil, or synthetic triglycerides, represented by B, is alsoprovided. Monomer A or the polymer block PA is polymerized with monomerB via reversible addition-fragmentation chain-transfer polymerization(RAFT), in the presence of a free radical initiator and a chain transferagent, to form the thermoplastic block copolymer. The polymerizing stepis carried out under conditions effective to achieve a number averagedegree of polymerization (N_(n)) for the thermoplastic block copolymerof up to 100,000 without gelation.

Alternatively, the method of preparing a thermoplastic block copolymercomprises providing a radically polymerizable triglyceride or mixturethereof, in the form of a plant oil, animal oil, or synthetictriglycerides, represented by B, or a polymer block PB comprising one ormore units of monomer B. A radically polymerizable monomer, representedby A is also provided. Monomer B or the polymer block PB is polymerizedwith monomer A via RAFT, in the presence of a free radical initiator anda chain transfer agent, to form the thermoplastic block copolymer. Thepolymerizing step is carried out under conditions effective to achieve anumber average degree of polymerization (N_(n)) for the thermoplasticblock copolymer of up to 100,000 without gelation.

Another aspect of the present invention relates to a method of preparinga thermoplastic homopolymer. The method comprises providing a radicallypolymerizable triglyceride or mixture thereof, in the form of a plantoil, animal oil, or synthetic triglycerides. This triglyceride-basedmonomer is then polymerized via RAFT, in the presence of a free radicalinitiator and a chain transfer agent, to form the thermoplastichomopolymer. The polymerizing step is carried out under conditionseffective to achieve a number average degree of polymerization (N_(n))for the thermoplastic homopolymer of up to 100,000 without gelation.

Another aspect of the present invention relates to a method of preparinga thermoplastic statistical copolymer. The method comprises providing aradically polymerizable monomer, represented by A. A radicallypolymerizable triglyceride or mixture thereof, in the form of a plantoil, animal oil, or synthetic triglycerides, represented by B is alsoprovided. Monomer A and monomer B are simultaneously polymerized, viaRAFT, in the presence of a free radical initiator and a chain transferagent to form the thermoplastic statistical copolymer. The polymerizingstep is carried out under conditions effective to achieve a numberaverage degree of polymerization (N_(n)) for the thermoplasticstatistical copolymer of up to 100,000 without gelation.

The present invention involves the successful application of reversibleaddition-fragmentation chain transfer polymerization (RAFT) tobiofeedstocks such as soybean oil, comprised predominantly of mixturesof triglycerides. The distinctive feature of this chemistry is that itallows the design of the molecular architecture of the resultantpolymers such that they are predominantly non-crosslinked linear orlightly branched chains that behave as elastomers/rubbers at roomtemperature but reversibly melt and are susceptible to common processingtechniques at elevated temperatures. RAFT has received a great deal ofattention with respect to petrochemical feedstocks, but it has not beensuccessfully applied to biofeedstocks such as soybean oil. The successof the technology on vegetable oils such as soybean oil is surprising,as conventional radical polymerization typically brings thepolymerization of triglycerides into thermoset materials, whereas thepresent invention successfully controls the polymerization oftriglyceride so that it terminates at a desired molecular weight andblock composition and produces thermoplastic polysoybean oil.

RAFT polymerization limits the number of initiation sites anddrastically reduces the rate of polymer-to-polymer chain transfer andtermination reactions, and also introduces the capability to producecustom chain architectures such as block copolymers (BCPs) andstatistical copolymers. This degree of control is superior to thatoffered by other controlled radical polymerization methods—that is,polymers of higher molar mass may be obtained over a shorter period oftime with less rigorous purification.

Typical monomers for chain-growth derived thermoplastic polymers aremonofunctional, that is, the monomer contains only a singlepolymerizable functional group. Triglycerides contain a number of doublebonds (which varies greatly within parent plant oil or animal oilspecies and even between cultivars of the same species) and so astriglyceride monomers for polymerization will exhibit at least twovarying functionalities. Accordingly, each polytriglyceride repeat unithas the potential to crosslink with at least one other polytriglyceride;when approximately a fraction of 1/N of such units have crosslinked (Ndenotes the number of repeat units in a polymer chain), the polymers aresaid to be at their “gel point” at which an infinite polymer network hasformed and the material is a thermoset.

In conventional RAFT polymerization, the classical Flory-Stockmeyertheory as well as a newer treatment of controlled radicalpolymerizations by GENNADY V. KOROLYOV AND MICHAEL MOGILEVICH,THREE-DIMENSIONAL FREE-RADICAL POLYMERIZATION CROSS-LINKED ANDHYPER-BRANCHED POLYMERS (Springer, Berlin, 2009), which is incorporatedherein by reference in its entirety, predicts a gelation at a criticalconversion rate α_(cr) given by α_(cr)(N_(w)−1)=1. According to thisclassical theory, the gel point is expected to occur at a criticalconversion α_(cr)<0.1 for multifunctional monomer; i.e. gelation isexpected to occur while the forming polymers are still in theiroligomeric stage. Thus, when the reactivity of a propagating chaintowards all functional sites on both free monomers and repeat units thatare already incorporated into a chain are identical, the expectation isthat the gel point will be reached at an extremely low conversion, suchthat, prior to gelation, the polytriglyceride has not yet achieved adegree of polymerization sufficient for useful mechanical properties todevelop. This expectation is supported by the past two decades ofreports of thermosets from vegetable oils produced by conventionalcationic and free radical polymerization. The expectation of earlygelation would also extend to RAFT if the reactivity ratios betweenpropagating radials and all unreacted functional sites on thetriglycerides were rigorously identical.

However, the RAFT method of the present invention enables a monomerconversion (which is defined as the mass ratio of the polymers producedto the monomers provided) of roughly 90%. In accordance with the presentinvention, preferences for free monomers can be exacerbated through theappropriate selection of a chain transfer agent and its ratio relativeto the monomer; reaction temperature; and a solvent and itsconcentration. Under such conditions, it is possible to producepolymerized triglycerides to targeted number average degree ofpolymerization (N_(n)) for the thermoplastic polymer of up to 100,000prior to the gel point. The use of highly excess CTA agent promotes theincorporation of CTA fragments into the polymer backbone. This in turncauses hyper-branching to occur rather than cross-linking in thepolymer. Thus, the polymerized triglycerides via RAFT of the presentinvention can reach number average degree of polymerization (N_(n)) forthe thermoplastic polymer of up to 100,000 without gelation.

Polymerized triglycerides, such as those found in soybean oil, areintrinsically renewable, are environmental friendly, and may also beshown to exhibit biodegradability. The elastomeric properties of thevegetable oil polymer appear to be competitive with modern commoditiessuch as polybutadiene (synthetic rubber). Further, the cost of thevegetable oil monomer has become highly competitive in recent years. Inmany cases the biomonomers are more economical than petrochemicalfeedstocks (e.g., a ton of vegetable oil costs less than $1,200, whereasa ton of butadiene costs greater than $4,000). Thus, the novelthermoplastic homopolymers, block copolymers or statistical copolymersof the present invention provide a cost-effective, environment-friendly,viable alternatives for the conventional petrochemically-derivedpolymeric materials.

These polymerized triglyceride-based thermoplastic homopolymers, blockcopolymers, or statistical copolymers are suitable in variousapplications, such as asphalt modifiers or viscosity modifier forconsumer care products, adhesives, sealants, rubber compositions, in theautomobile industry, footwear, packaging, in the consumer electronics,etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing illustrating the preparation ofbio-polymeric thermoplastic elastomers (TPE) from soybean oil via RAFTpolymerization mechanism, described in Moad et al., “Living RadicalPolymerization by the Raft Process—a First Update,” Australian Journalof Chemistry 59: 669-92 (2006), which is incorporated herein byreference in its entirety.

FIG. 2 is a schematic drawing depicting usages of the plant oil- oranimal oil-based thermoplastic elastomers in various markets.

FIG. 3 is a flowchart showing the process of blending ofpoly(styrene-SBO-styrene) block copolymer compositions with asphaltbinders and then testing their rheological properties.

FIG. 4 shows the chemical structure of azobisisobutyronitrile (AIBN).

FIG. 5 shows the chemical structure of 1-phenylethyl benzodithioate.

FIG. 6 is a graph showing the molecular weight (number average) increaseof a styrene homopolymer as a function of time.

FIG. 7 is a graph showing the molecular weight (number average) increaseof a poly(styrene-b-AESO) diblock copolymer as a function of time.

FIG. 8 is a photographic image showing a 130,000 kD/molpoly(styrene-b-AESO) diblock.

FIG. 9 is a graph showing an increase in molecular weight from amonomer, to a homopolymer, and to a diblock copolymer.

FIG. 10 is a photographic image showing a poly(styrene-b-AESO-styrene)triblock after 24 hours in the vacuum oven.

FIG. 11 is a graph showing the nuclear magnetic resonance (NMR) spectraof the poly(styrene-b-AESO-styrene) triblock.

FIG. 12 is a graph showing the results of differential scanningcalorimetry (DSC) of a PS-PAESO-PS sample. A glass transitiontemperature is shown in the graph at −10° C.; no apparent glasstransition is present for the PS block.

FIG. 13 is a graph showing the rheology curve of a PS-PAESO-PS sample.

FIG. 14 is a graph showing the results of the tensile test of apoly(styrene-b-AESO-styrene) triblock copolymer: the load (MPa) versustensile strain (mm/mm).

FIG. 15 is a graph showing the stress versus % strain curves for a RAFTsynthesized PS-PAESO-PS triblock copolymer continued loading (gray) tofind the maximum stress.

FIG. 16 is a TEM image of the PS-PAESO-PS #1 sample, listed in Table 2.The image shows a semi-ordered structure where the black islands are thestyrene blocks and the lighter regions are the AESO blocks.

FIG. 17 is a graph showing the stress vs. % strain curves forPS-PAESO-PS #1, listed in Table 2. The first load is depicted by theblue line, which was followed by the first hysteresis cycle (black), thetenth cycle (red), and then further continued loading (gray) to find themaximum stress.

FIG. 18 is a graph showing the Young's Modulus of the PS-PAESO-PS#1,listed in Table 2, during the load and unload cycles.

FIG. 19 is a graph comparing the ¹H-NMR spectra of the corn oil, theepoxidized corn oil, and the acrylated epoxidized corn oil.

FIG. 20 is a graph comparing the ¹H-NMR spectra of AECO monomer (top)and an AECO homopolymer with an average molecular weight of 6,512 Daafter 9 hours of reaction (bottom).

FIG. 21 is a graph showing the ¹H-NMR spectra of the PS-PAESO-PStriblock copolymer synthesized using a telechelic CTA, having amolecular weight of 426 kDa and polydispersity of 1.26.

FIG. 22 is a graph showing the differential refractive index collectedusing gel permeation chromatography of a PAESO-containing triblockcopolymer synthetized with a telechelic CTA.

FIG. 23 is a graph showing the GPC curves for the PAECO and PShomopolymers, and a PS-PAECO-PS triblock copolymers synthesized using atelechelic CTA.

FIG. 24 is a graph showing the differential refractive index collectedusing gel permeation chromatography of an AESO-containing statisticalcopolymer.

FIG. 25 is a graph showing the differential refractive index collectedusing gel permeation chromatography of an acrylated epoxidized corn oil(AECO)-containing statistical copolymer.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the present invention relates to a thermoplastic blockcopolymer comprising at least one PA block and at least one PB block.The PA block represents a polymer block comprising one or more units ofmonomer A, and the PB block represents a polymer block comprising one ormore units of monomer B. Monomer A is a vinyl, acrylic, diolefin,nitrile, dinitrile, acrylonitrile monomer, a monomer with reactivefunctionality, or a crosslinking monomer. Monomer B is a radicallypolymerizable triglyceride or mixture thereof, typically in the form ofa plant oil, animal oil, or synthetic triglycerides. One end or bothends of the PA block or PB block in the thermoplastic block copolymeris/are functionalized with a thiocarbonylthio chain transfer group. Forexample, the polymer chain can have one end or both ends with athiocarbonylthio ending derived from the thiocarbonylthio chain transfergroup—like (P_(n)S(Z)C=S, 3), as shown in FIG. 1. The thiocarbonylthiochain transfer group has been described herein. A more extensive list ofthiocarbonylthio CTA agents (or RAFT agents) can be found in Moad etal., “Living Radical Polymerization by the Raft Process—a First Update,”Australian Journal of Chemistry 59: 669-92 (2006); Moad et al., “LivingRadical Polymerization by the Raft Process—a Second Update,” AustralianJournal of Chemistry 62(11):1402-72 (2009); Moad et al., “Living RadicalPolymerization by the Raft Process—a Third Update,” Australian Journalof Chemistry 65: 985-1076 (2012); Skey et al., “Facile one pot synthesisof a range of reversible addition-fragmentation chain transfer (RAFT)agents,” Chemical Communications 35: 4183-85 (2008), which are herebyincorporated by reference in their entirety.

The thermoplastic block copolymer can be a linear or light-branchedcopolymer, and can contain two or more blocks. Exemplary copolymerarchitecture includes, but is not limited to (PA-PB)_(n),(PA-PB)_(n)-PA, and PB-(PA-PB)_(n). n is an integer greater than 0. Forexample, n ranges from 1 to 50, from 1 to 10, or from 1 to 5. The blockcopolymer typically has a di-block polymer architecture (PA-PB),tri-block polymer architecture (PA-PB-PA or PB-PA-PB) or penta-blockpolymer architecture (PA-PB-PA-PB-PA or PB-PA-PB-PA-PB). The blocks ofthe copolymer are formed by sequential additions alternating betweenmonomer A and monomer B until the desired multiblock architecture hasbeen achieved. Each monomer A unit or monomer B unit in architecture maybe the same or different.

Another aspect of the present invention relates to a telechelicthermoplastic block copolymer having an architecture of(PA-PB)_(n)-TCTA-(PB-PA)_(n) or (PB-PA)_(n)-TCTA-(PA-PB)_(n), where n isan integer ranging from 1 to 10. TCTA is a moiety in the PB block or PAblock from a telechelic chain transfer agent used to produce thetelechelic thermoplastic block copolymer. The PA block represents apolymer block comprising one or more units of monomer A, and the PBblock represents a polymer block comprising one or more units of monomerB. Monomer A is a vinyl, acrylic, diolefin, nitrile, dinitrile,acrylonitrile monomer, a monomer with reactive functionality, or acrosslinking monomer. Monomer B is a radically polymerizabletriglyceride or mixtures thereof, in the form of a plant oil, animaloil, or synthetic triglycerides. TCTA is a moiety derived from a“telechelic chain transfer agent”, e.g., a trithiocarbonate moiety orany other moiety from a telechelic CTA agent used to produce thetelechelic thermoplastic block copolymers. n is an integer ranging from1 to 50, or from 1 to 10. The structures and mechanism of making thetelechelic thermoplastic block copolymers have been described herein.

The telechelic thermoplastic block copolymer can be a linear orlight-branched copolymer, and can contain three or more blocks. Theblock copolymer typically has symmetrical tri-block polymer architecture(PA-PB-TCTA-PB-PA or PB-PA-TCTA-PA-PB) or a penta-block polymerarchitecture (PA-PB-PA-TCTA-PA-PB-PA or PB-PA-PB-TCTA-PB-PA-PB). TCTA isa moiety derived from a telechelic chain transfer agent in the PB block(PB-TCTA-PB) or in the PA block (PA-TCTA-PA). Each monomer A unit ormonomer B unit in the architecture may be the same or different,provided that the overall architecture is symmetrical, e.g.,PA₁-PB-PA₂-PB-PA₁ (A₁ and A₂ refer to different kinds of monomer formonomer unit A).

The PA block is made by polymerizing one or more radically polymerizablemonomers, and has an average molecular weight of about 1 to about 1000kDa, or about 10 to about 30 kDa. The PA block may comprise repeatingunits of monomer A. For instance, the PA block can be a polymerizedlinear-chain or branched-chain monomer A or radicals thereof. The PBblock is made by polymerizing one or more triglyceride or mixtures oftriglycerides, typically in the form of a plant oil, animal oil, orsynthetic triglycerides, and has an average molecular weight of about 5to about 1000 kDa, about 10 to about 500 kDa, about 40 to about 100 kDa,or about 80 to about 100 kDa. The PB block may comprise repeating unitsof triglyceride or mixtures of triglycerides. For instance, the PB blockcan be a polymerized linear-chain or branched-chain monomeric plant oilor animal oil, or radicals thereof.

PA-PB di-block copolymers typically contain about 5 wt % to about 95 wt% of the polymerized A block and about 95 wt % to about 5 wt % ofpolymerized triglyceride block. PA-PB-PA or PB-PA-PB tri-blockcopolymers typically contain about 5 wt % to about 95 wt % of thepolymerized A block and about 95 wt % to about 5 wt % of polymerizedtriglyceride block. PA-PB-PA-PB-PA or PB-PA-PB-PA-PB penta-blockcopolymers typically contain about 5 wt % to about 95 wt % of thepolymerized A block and about 95 wt % to about 5 wt % of polymerizedtriglyceride block. For instance, the above block copolymers may containabout 10 wt % to about 90 wt % of the polymerized A block and about 90wt % to about 10 wt % of polymerized triglyceride block. Adjusting therelative percentage composition of the PA or the PB block can tune theproperty of the block copolymer to make it more suitable for differentapplications. For example, block copolymers containing a relatively lowconcentration of PA block are suitable for elastomers/adhesives whereasa block copolymer containing a relatively high concentration of PAblocks are suitable for tough engineering materials (e.g. likePlexiglas® or high-impact polystyrene).

The PA block of the block copolymer can be considered as a “hard” block,and has properties characteristic of thermoplastic substances in that ithas the stability necessary for processing at elevated temperatures andyet possesses good strength below the temperature at which it softens.The PA block is polymerized from one or more radically polymerizablemonomers, which can include a variety type of monomers such as vinyl(such as vinyl aromatic), acrylic (such as methacrylates, acrylates,methacrylamides, acrylamides, etc.), diolefin, nitrile, dinitrile,acrylonitrile monomer, a monomer with reactive functionality, and acrosslinking monomer.

Vinyl aromatic monomers are exemplary vinyl monomers that can be used inthe block copolymer, and include any vinyl aromatics optionally havingone or more substituents on the aromatic moiety. The aromatic moiety canbe either mono- or polycyclic. Exemplary vinyl aromatic monomers for thePA block include styrene, α-methyl styrene, t-butyl styrene, vinylxylene, vinyl naphthalene, vinyl pyridine, divinyl benzene, N-vinylheteroaromatics (such as 4-vinylimidazole (Vim), N-vinylcarbazole (NVC),N-vinylpyrrolidone, etc.). Other exemplary vinyls include vinyl esters(such as vinyl acetate (VAc), vinyl butyrate (VB), vinyl benzoate(VBz)), N-vinyl amides and imides (such as N-vinylcaprolactam (NVCL),N-vinylpyrrolidone (NVP), N-vinylphthalimide (NVPI), etc.),vinylsulfonates (such as 1-butyl ethenesulfonate (BES), neopentylethenesulfonate (NES), etc.), vinylphosphonic acid (VPA), haloolefins(such as vinylidene fluoride (VF2)), etc. Exemplary methacrylatesinclude C₁-C₆ (meth)acrylate (i.e., methyl methacrylate, ethylmethacrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutylmethacrylate, heptyl (meth)acrylate, or hexyl (meth)acrylate),2-(acetoacetoxy)ethyl methacrylate (AAEMA), 2-aminoethyl methacrylate(hydrochloride) (AEMA), allyl methacrylate (AMA), cholesterylmethacrylate (CMA), t-butyldimethylsilyl methacrylate (BDSMA),(diethylene glycol monomethyl ether) methacrylate (DEGMA),2-(dimethylamino)ethyl methacrylate (DMAEMA), (ethylene glycolmonomethyl ether) methacrylate (EGMA), 2-hydroxyethyl methacrylate(HEMA), dodecyl methacrylate (LMA), methacryloyloxyethylphosphorylcholine (MPC), (poly(ethylene glycol) monomethyl ether)methacrylate (PEGMA), pentafluorophenyl methacrylate (PFPMA),2-(trimethylamonium)ethyl methacrylate (TMAEMA),3-(trimethylamonium)propyl methacrylate (TMAPMA), triphenylmethylmethacrylate (TPMMA), etc. Other exemplary acrylates include2-(acryloyloxy)ethyl phosphate (AEP), butyl acrylate (BA),3-chloropropyl acrylate (CPA), dodecyl acrylate (DA), di(ethyleneglycol) 2-ethylhexyl ether acrylate (DEHEA), 2-(dimethylamino)ethylacrylate (DMAEA), ethyl acrylate (EA), ethyl a-acetoxyacrylate (EAA),ethoxyethyl acrylate (EEA), 2-ethylhexyl acrylate (EHA), isobornylacrylate (iBoA), methyl acrylate (MA), propargyl acrylate (PA),(poly(ethylene glycol) monomethyl ether) acrylate (PEGA), tert-butylacrylate (tBA), etc. Exemplary methacrylamides includeN-(2-aminoethyl)methacrylamide (hydrochloride) (AEMAm) andN-(3-aminopropyl)methacrylamide (hydrochloride) (APMAm),N-(2-(dimethylamino)ethyl)acrylamide (DEAPMAm),N-(3-(dimethylamino)propyl)methacrylamide (hydrochloride) (DMAPMAm),etc. Other exemplary acrylamides include acrylamide (Am)2-acrylamido-2-methylpropanesulfonic acid sodium salt (AMPS),N-benzylacrylamide (BzAm), N-cyclohexylacrylamide (CHAm), diacetoneacrylamide (N-(1,1-dimethyl-3-oxobutyl) acrylamide) (DAAm),N,N-diethylacrylamide (DEAm), N,N-dimethylacrylamide (DMAm),N-(2-(dimethylamino)ethyl)acrylamide (DMAEAm), N-isopropylacrylamide(NIPAm), N-octylacrylamide (OAm), etc. Exemplary nitriles includeacrylonitrile, adiponitrile, methacrylonitrile, etc. Exemplary diolefinsinclude butadiene, isoprene, etc.

The radically polymerizable monomers suitable for usage herein alsoinclude those monomers with reactive functionality, e.g., a ‘clickable’functionality so that when the monomers are incorporated in blocks,these ‘clickable’ functional groups can be used as a precursor to apolymer brush or copolymerized to provide sites for the attachment offunctionality or for crosslinking. Exemplary reactive functionalityinclude functional groups suitable for azide-alkyne 1,3-dipolarcycloaddition, such as azide functionality; “active ester’ functionalgroups that are particular active with primary amine functionality;functional groups with protected thiol, hydrazide or aminofunctionality; functional groups with isocyanate or isothiocyanatefunctionality, etc.

The radically polymerizable monomers suitable for usage herein can alsoinclude those crosslinking monomers that are typically used both in thesynthesis of microgels and polymer networks (see below). The monomerscan include degradable crosslinks such as an acetal linkage, ordisulfide linkages, resulting in the formation of degradable crosslinks.Exemplary crosslinking monomers diethyleneglycol dimethacrylate(DEGDMA), triethylene glycol dimethacrylate (TEGDMA), ethyleneglycoldimethacrylate (EGDMA), hexane-1,6-diol diacrylate (HDDA),methylene-bis-acrylamide (MBAm), divinylbenzene (DVB), etc.

A more extensive list of exemplary methacrylate monomers, acrylatemonomers, methacrylamide monomers, acrylamide monomers, styrenicmonomers, diene monomers, vinyl monomers, monomers with reactivefunctionality, and crosslinking monomers that are suitable for usage asthe radically polymerizable monomers herein has been described in Moadet al., “Living Radical Polymerization by the Raft Process—a ThirdUpdate,” Australian Journal of Chemistry 65: 985-1076 (2012), which ishereby incorporated by reference in its entirety.

Moreover, two or more different monomers can be used together in theformation of the PA block or different PA block in the copolymer. Atypical radically polymerizable monomer A used herein is styrene, andthe resulting PA block is a styrene homopolymer. Another typicalradically polymerizable monomer A used herein is methyl acrylate, andthe resulting PA block is a methyl acrylate homopolymer.

The PB block of the block copolymer can be considered as a “soft” block,and has elastomeric properties which allow it to absorb and dissipate anapplied stress and then regain its shape. The PB block is polymerizedfrom one or more monomeric triglycerides, typically derived from a plantoil, animal fat, or a synthetic triglyceride. This polymerized plant oilor animal oil can be subsequently partially or fully saturated via acatalytic hydrogenation post-polymerization. The monomeric oils used inthe block copolymer can be any triglycerides or triglyceride mixturesthat are radically polymerizable. These triglycerides or triglyceridemixtures are typically plant oils. Suitable plant oils include, but arenot limited to, a variety of vegetable oils such as soybean oil, peanutoil, walnut oil, palm oil, palm kernel oil, sesame oil, sunflower oil,safflower oil, rapeseed oil, linseed oil, flax seed oil, colza oil,coconut oil, corn oil, cottonseed oil, olive oil, castor oil, false flaxoil, hemp oil, mustard oil, radish oil, ramtil oil, rice bran oil,salicornia oil, tigernut oil, tung oil, etc., and mixtures thereof.Typical compositions of several exemplary vegetable oils are shown inTable 1. Typical vegetable oil used herein includes soybean oil, linseedoil, corn oil, flax seed oil, or rapeseed oil, and the resulting PBblock is polymerized triglyceride or triglyceride derivatives.

TABLE 1 Typical compositions of vegetable oils. Vegetable Linoleic Poly-Mono- oil acid (%) unsaturated (%) unsaturated (%) Saturated (%) Soybean54 63 22 15 Safflower 78 78 13 9 Sunflower 75 75 14 11 Walnut 64 64 2214 Corn 59 60 27 13 Sesame 43 43 43 14 Peanut 31 31 51 18

Vegetable oils and animal fats are mixtures of triglycerides. Arepresentative structure of a triglyceride is shown as below:

A typical triglyceride structure contains a number of double bonds thatmay serve as candidates for polymerization. Various soybean cultivarsexpress a variety of triglyceride compositions in their oils. Differentstrains of soybeans may be appropriately selected based on thetriglyceride compositions to enhance the block copolymer yield andproperties.

Soybean Oil (SBO) is the most abundant vegetable oil, which accounts foralmost 30% of the world's vegetable oil supply. SBO is particularlysuitable for polymerization, because it possesses multiple carbon-carbondouble bonds that allow for modifications such as conjugation of thedouble bonds, etc.

In unprocessed oils, the double bonds contained in triglycerides aretypically located in the middle of the alkyl chains, and have limitedreactivity towards propagation reactions due to steric hindrance andunfavorable stability of the free radical. This reactivity improvesdramatically when the double bonds are conjugated (Li et al., “SoybeanOil-Divinylbenzene Thermosetting Polymers: Synthesis, Structure,Properties and their Relationships,” Polymer 42(4):1567-1579 (2001);Henna et al., “Biobased Thermosets from Free Radical Copolymerization ofConjugated Linseed Oil,” Journal of Applied Polymer Science 104:979-985(2007); Valverde et al., “Conjugated Low-Saturation Soybean OilThermosets: Free-Radical Copolymerization with Dicyclopentadiene andDivinylbenzene,” Journal of Applied Polymer Science 107:423-430 (2008);Robertson et al., “Toughening of Polylactide with Polymerized SoybeanOil,” Macromolecules 43:1807-1814 (2010), which are hereby incorporatedby reference in their entirety). The conjugation of double bonds intriglycerides may be readily achieved to nearly 100% conversion withhomogeneous Rh catalysis (Larock et al., “Preparation of ConjugatedSoybean Oil and Other Natural Oils and Fatty Acids by HomogeneousTransition Metal Catalysis,” Journal of the American Oil Chemists'Society 78:447-453 (2001), which is hereby incorporated by reference inits entirety).

In any embodiment of the present invention, the polymerizable plant oilmonomer containing triglyceride can be replaced with a polymerizablemonomer containing one or more triglycerides from an animal source, forinstance, animal fats. Thus, the PB block in any embodiment of thepresent invention can instead be polymerized from one or more monomericanimal fat containing one or more triglycerides. Examples of suitableanimal fats used in accordance with the present invention include, butare not limited to, beef or mutton fat such as beef tallow or muttontallow, pork fat such as pork lard, poultry fat such as turkey and/orchicken fat, and fish fat/oil. The animal fats can be obtained from anysuitable source including restaurants and meat production facilities.

“Triglycerides,” as defined herein, may refer to any unmodifiedtriglycerides naturally existent in plant oil or animal oil or animalfat as well as any derivatives of unmodified triglycerides, such assynthetically derived triglycerides. The naturally existent parent oilmay also contain derivatives of triglycerides, such as free fatty acids.An unmodified triglyceride may include any ester derived from glycerolwith three similar or different fatty acids. Triglyceride derivativesmay include any modified triglycerides that contain conjugated systems(i.e. a system of connected p-orbitals with delocalized electrons intriglycerides). Such conjugated systems increase the reactivity oftriglycerides towards propagation reactions. Useful conjugatedtriglycerides include, but are not limited to, triglyceride derivativescontaining conjugated double bonds or conjugated systems formed byacrylate groups.

The term “soybean oil” used herein may refer broadly to any raw soybeanoil or processed soybean oil that contains at least one form oftriglyceride or its derivative suitable for the polymerization reactionof the present invention. The term “conjugated soybean oil” used hereinrefers to any raw soybean oil or processed soybean oil containing atleast one triglyceride with at least one conjugated site. Similardefinitions also apply to other plant oils, animal oils, conjugatedplant oils, conjugated animal oils, or synthetically derivedtriglyceride-based oils.

The conjugated triglyceride may contain one or more conjugated sites.For instance, the conjugated triglyceride may contain a singleconjugated site per triglyceride. Alternatively, each fatty-acid chainof the triglyceride may contain one or more conjugated sites.

Exemplary conjugated triglycerides are:

A further description of conjugation sites in soybean oil, epoxidationof soybean oil, and acrylation of soybean oil can be found in NACUBERNARDO HERNANDEZ-CANTU, “SUSTAINABILITY THROUGH BLOCKCOPOLYMERS—NOVELION EXCHANGE CATHODE MEMBRANES AND SOYBEAN OIL BASED THERMOPLASTICELASTOMER,” (Iowa State University, Ames, Iowa 2012), which isincorporated herein by reference in its entirety.

In one embodiment, the conjugated plant oil or animal oil is acrylatedepoxidized plant oil or animal oil, such as acrylated epoxidized soybeanoil or acrylated epoxidized corn oil; the conjugated triglyceride isacrylated epoxidized triglyceride.

In any embodiment of the present invention, the block copolymer is athermoplastic elastomer. The mechanism for achieving the dual propertiesof thermoplasticity and elasticity/toughness in the plant oil or animaloil-based styrenic block copolymer arises from polymer thermodynamicsand the chain architecture of the polymer. Flory-Huggins theoryillustrates that nearly all polymers are mutually immiscible, due to thedrastic loss of mixing entropy. The chemically dissimilar monomersequences found in the block copolymers may be thought of conceptuallyas immiscible homopolymers bound covalently end-to-end. Due to thisconstraint, when a block copolymer phase separates, incompatible polymertypes form meso-domains with a geometry dictated by the blockcomposition and with a size governed by the overall molecular weight(Bates et al. “Block Copolymers-Designer Soft Materials,” Physics Today52(2):32-38 (1999), which is hereby incorporated by reference in itsentirety). In block copolymers with modest polydispersity, thesemeso-domains have well-defined geometries and become statistical innature as the polydisersity index increases beyond approximately 1.5(Widin et al, “Unexpected Consequences of Block Polydispersity on theSelf-Assembly of ABA Triblock Copolymers”, Journal of the AmericanChemical Society, 134(8):3834-44 (2012), which is hereby incorporated byreference in its entirety).

In a typical SBS elastomer, the styrene composition is about 10-30 wt %such that spherical or cylindrical styrene domains form in a matrix ofbutadiene. When the temperature is below the glass transitiontemperature of polystyrene (T_(g)=100° C.), the polybutadiene matrix isliquid (T_(g)<−90° C.) but is bound between the vitreous polystyrenespheres, which serve as physical crosslinks. When the temperature isabove the glass transition temperature of polystyrene, the entireelastomer system is molten and may be processed easily. Crosslinkedpoly(soybean oil) has been reported to have T_(g) values as low as −56°C. (Yang et al., “Conjugation of Soybean Oil and It's Free-RadicalCopolymerization with Acrylonitrile,” Journal of Polymers and theEnvironment 1-7 (2010), which is hereby incorporated by reference in itsentirety). Thus, the poly(soybean oil) is an excellent candidate toserve as the liquid component in thermoplastic elastomers based onstyrenic block copolymers.

Accordingly, in one embodiment of the present invention, thethermoplastic and elastomeric block copolymer has a PA-PB diblockpolymer architecture, where the PA block is a linear-chain polystyrene(PS) and the PB block is a linear or light-branched polymerized soybeanoil (PSBO) or radicals thereof, or polymerized conjugated soybean oil(PCSBO) or radicals thereof. The PS-PSBO di-block copolymer has amolecular weight ranging from 5 to 10,000 kDa, for instance, from 5 to500 kDa, from about 15 to 300 kDa, from about 40 to about 100 kDa, orfrom about 80 to about 100 kDa. The PSBO block has a glass transitiontemperature (T_(g)) below −10° C., or below −15° C., for instance, fromabout −60° C. to about −12° C., or from about −60° C. to about −28° C.

In one embodiment of the present invention, the thermoplastic andelastomeric block copolymer has a PA-PB-PA triblock polymerarchitecture, where the PA block is a linear-chain polystyrene (PS), andthe PB block is a linear or light-branched polymerized soybean oil(PSBO) or radicals thereof, or polymerized conjugated soybean oil(PCSBO) or radicals thereof. This soybean oil-based styrenic triblockcopolymer (PS-PSBO-PS) thus has an elastomeric interior block PSBO, anda thermoplastic outer block PS formed on both ends of the interior blockPSBO. The PS-PSBO-PS tri-block copolymer has a molecular weight rangingfrom 7 kDa to 10,000 kDa, for instance, from 7 kDa to 1000 kDa, fromabout 7 to about 500 kDa, from about 15 to about 350 kDa, from about 80to about 120 kDa or from about 100 to about 120 kDa. The PSBO block hasa T_(g) below −10° C., or below −15° C., for instance, from about −60°C. to about −12° C., or from about −60° C. to about −28° C.

In one embodiment, the triglyceride mixture to be radically polymerizedis soybean oil, linseed oil, flax seed oil, corn oil, or rapeseed oil.In one embodiment, acrylated epoxidized triglyceride mixture, such asacrylated epoxidized soybean oil, is radically polymerized in accordancewith the method of the present invention.

Another aspect of the present invention relates to a thermoplasticstatistical copolymer having a general formula of[A_(i)-B_(j)-C_(k)]_(q). In the formula, A represents monomer A, whichis a vinyl, acrylic, diolefin, nitrile, dinitrile, acrylonitrilemonomer, a monomer with reactive functionality, or a crosslinkingmonomer. B represents monomer B, which is a radically polymerizabletriglyceride or mixture thereof, in the form of a plant oil, animal oil,or synthetic triglycerides. C represents monomer C, which is a vinyl,acrylic, diolefin, nitrile, dinitrile, acrylonitrile monomer, a monomerwith reactive functionality, or a crosslinking monomer; or a radicallypolymerizable triglyceride or mixture thereof, typically in the form ofa plant oil, animal oil, or synthetic triglycerides, provided monomer Cis different than the monomer A or monomer B. i, j, and k are averagenumber of repeating units of monomer A, monomer B, and monomer C,respectively, such that i and j are each greater than 0 and less than 1,k is 0 to less than 1, provided i+j+k=1. q represents the number averagedegree of polymerization and ranges from 10 to 100,000, for instancefrom 10 to 10,000, or from 500 to 1500.

The thermoplastic statistical copolymer can be linear or branched andcan contain statistical sequences of A, B, or C monomer. A represents amonomer unit A, which is radically polymerizable. Monomer unit Arepresents a “hard” segment which confers the thermoplastic statisticalcopolymer the stability necessary for processing at elevatedtemperatures and at the same time good strength below the temperature atwhich it softens. B represents a monomer unit B, which is a radicallypolymerizable triglyceride or mixtures of triglycerides. Monomer unit Brepresents a “soft” segment which confers the thermoplastic statisticalcopolymer elastomeric characteristics which allows it to absorb anddissipate an applied stress and then regain its shape. C represents amonomer unit C, which is also radically polymerizable. Monomer C mayeither represent a “hard” segment similar as monomer A or represent a“soft” segment similar as monomer B, but represent monomer differentthan either A or B. The average repeat sequence within the statisticalcopolymer is highly dependent upon the relative reactivity ratios forthe addition of monomer type j to growing radical type i.

Monomer A or monomer C can be each independently a vinyl, acrylic,diolefin, nitrile, dinitrile, acrylonitrile monomer, or monomer withreactive functionality, or crosslinking monomer. The exemplaryembodiments for monomer A and monomer C suitable for usage in thethermoplastic statistical copolymer are the same as the exemplaryembodiments for the monomer A, as described above in the thermoplasticblock copolymer. Exemplary monomer A and monomer C include styrene,α-methyl styrene, t-butyl styrene, vinyl xylene, vinyl naphthalene,vinyl pyridine, divinyl benzene, vinyl acetate, N-vinylpyrrolidone,methyl acrylate, C₁-C₆ (meth)acrylate (i.e., methyl methacrylate, ethylmethacrylate, propyl (meth)acrylate, butyl (meth)acrylate, heptyl(meth)acrylate, or hexyl (meth)acrylate), acrylonitrile, adiponitrile,methacrylonitrile, butadiene, isoprene, or mixtures thereof. In oneembodiment, the monomer A and the monomer C are each independently avinyl aromatic monomer, for instance, a styrene. In another embodiment,the monomer A or the monomer C is each independently an acrylatemonomer, for instance, a methyl (meth)acrylate.

Monomer B can be a monomeric triglyceride or mixture thereof stemmingfrom any plant oil, animal oil, or synthetic triglyceride that isradically polymerizable, particular those that contain one or more typesof triglycerides. Suitable plant oils include, but are not limited to, avariety of vegetable oils such as soybean oil, peanut oil, walnut oil,palm oil, palm kernel oil, sesame oil, sunflower oil, safflower oil,rapeseed oil, linseed oil, flax seed oil, colza oil, coconut oil, cornoil, cottonseed oil, olive oil, castor oil, false flax oil, hemp oil,mustard oil, radish oil, ramtil oil, rice bran oil, salicornia oil,tigernut oil, tung oil, etc., and mixtures thereof. Exemplary plant oilmonomer in the statistical copolymer is soybean oil, corn oil, linseedoil, flax seed oil, or rapeseed oil. In one embodiment, the polymerizedplant oil is poly(soybean oil). Suitable animal fats include, but arenot limited to, beef or mutton fat such as beef tallow or mutton tallow,pork fat such as pork lard, poultry fat such as turkey and/or chickenfat, and fish fat/oil. The animal fats can be obtained from any suitablesource including restaurants and meat production facilities. Thetriglyceride in the plant oil or animal oil can comprise one or moreconjugated sites, as described above. In one embodiment, thetriglyceride is an acrylated epoxidized triglyceride.

Monomer C can also be a radically polymerizable triglyceride or mixtureof triglycerides, but from a different plant oil, animal oil, orsynthetic triglyceride than the monomer B, or the triglycerides of themonomer C have a different degree of conjugation than that of monomer B.E.g., the triglycerides of the monomer C and the monomer B can eachindependently have different degrees of acrylic functionality, rangingfrom 1 per molecule to 5 per molecule. The embodiments and examples forthe monomer C as a radically polymerizable plant oil monomer or animaloil monomer are the same as the embodiments described above for monomerB.

In one embodiment, the monomer C is absent, the monomer A is styrene,the monomer B is soybean oil, linseed oil, corn oil, flax seed oil, orrapeseed oil.

In one embodiment, the monomer A is styrene, the monomer B is soybeanoil, linseed oil, corn oil, flax seed oil, or rapeseed oil, and themonomer C is a linear chain-extending monomer, such as diene, a rubberymonomer, such as n-butyl acrylate. A more extensive list of linearchain-extending monomers can be found in Moad et al., “Living RadicalPolymerization by the Raft Process—a Third Update,” Australian Journalof Chemistry 65: 985-1076 (2012), which is hereby incorporated byreference in its entirety.

Other aspects of the present invention relate to the use of thepolymerized plant oil- or animal oil-based thermoplastic blockcopolymers or thermoplastic statistical copolymers in a variety ofapplications. The benefit of utilizing the polymeric materials of thepresent invention is multifaceted. The thermoplastic block copolymersthermoplastic statistical copolymers of the present invention are basedon vegetable oils, such as soybean oils. Polymerized soybean oil isintrinsically biodegradable and the feedstock is produced through anegative carbon-emissions process (i.e., growing soybeans). Thus, thesepolymeric materials are attractive from an environmental/biorenewableperspective. Moreover, the elastomeric properties of the soybean oilpolymers are competitive with modern commodities such as polybutadieneand polyisoprene (synthetic rubber). The cost of the bio-monomer ishighly competitive (in many cases more economical thanpeterochemically-derived feedstocks). Further, with appropriatemodification of the soybean oil (such as conjugation of triglycerides,or development of soybean oil types that are particularly suitable forpolymerization), the chemical properties, thermal properties,microstructure and morphology, and mechanical/rheological behaviors ofthe soybean oil-based polymers can be improved and fine-tuned to makethese polymers highly useful in the plastics industry.

Exemplary applications of the thermoplastic block copolymers orthermoplastic statistical copolymers of the present invention includetheir use: as rubbers or elastomers; as toughened engineeringthermoplastics; as components in consumer electronics, such as componentfor shock/impact protection or cover components; as asphalt modifiers;as resin modifiers; as engineering resins; as leather and cementmodifiers; in footwear, such as in rubber shoe heels, rubber shoe soles;in automobiles, such as in tires, hoses, power belts, conveyor belts,printing rolls, rubber wringers, automobile floor mats, mud flaps fortrucks, ball mill liners, and weather strips; as sealants or adhesives,such as pressure sensitive adhesives; in aerospace equipment; asviscosity index improvers; as detergents; as diagnostic agents andsupports therefore; as dispersants; as emulsifiers; as lubricants and/orsurfactants; as paper additives and coating agents; and in packaging,such as food and beverage packaging materials. Exemplary applications ofthe plant oil- or animal oil-based thermoplastic elastomers in variousmarkets are shown in FIG. 2.

In some embodiments, the polymerized plant oil- or animal oil-basedthermoplastic block copolymers or thermoplastic statistical copolymersof the present invention can be used as a main component in athermoplastic elastomer composition, to improve the thermoplastic andelastic properties of the composition. To form an elastomericcomposition, the thermoplastic block copolymer can be furthervulcanized, cross-linked, compatibilized, and/or compounded with one ormore other materials, such as other elastomer, additive, modifier and/orfiller. The resulting elastomer can be used as a rubber composition, invarious industries such as in footwear, automobiles, packaging, etc.

In one embodiment, the polymerized plant oil- or animal oil-basedthermoplastic block copolymers or thermoplastic statistical copolymersof the present invention can be used in an automobile, such as invehicle tires, hoses, power belts, conveyor belts, printing rolls,rubber wringers, automobile floor mats, mud flaps for trucks, ball millliners, and weather strips. The thermoplastic block copolymers can serveas a main component in a thermoplastic elastomer composition, to improvethe thermoplastic and elastic properties of the automobile compositions(e.g., vehicle tires). The resulting compositions can be furthervulcanized, cross-linked, compatibilized, and/or compounded with one ormore other materials, such as other elastomer, additive, modifier and/orfiller.

In one embodiment, the polymerized plant oil- or animal oil-basedthermoplastic block copolymers or thermoplastic statistical copolymersof the present invention can be used in an asphalt composition, as anasphalt additive, modifier and/or filler. The asphalt composition mayfurther comprise a bitumen component. The asphalt composition maycomprise a wide range of the block copolymer. For instance, the asphaltcomposition comprises 1 to 5 wt % of the thermoplastic block copolymeror thermoplastic statistical copolymers.

In one embodiment, the polymerized plant oil- or animal oil-basedthermoplastic block copolymers or thermoplastic statistical copolymerscan be used in an adhesive composition. The adhesive composition mayfurther comprise a tackifier and/or a plasticizer.

In one embodiment, the polymerized plant oil- or animal oil-basedthermoplastic block copolymers or thermoplastic statistical copolymerscan be used in a toughened engineering thermoplastic composition. Atoughened engineering thermoplastic composition typically comprisespredominantly a glassy or semicrystalline component with a minority ofrubbery or elastomeric component to increase the toughness (reduce thebrittleness) of the material, e.g. analogous to High-Impact Polystyrene(HIPS). To form a toughened engineering thermoplastic composition, theblock copolymer of the present invention may be formulated such that theplant-oil block is a minority component and serves to absorb energy thatwould otherwise lead to the fracture of the solid matrix. The blockcopolymer or the statistical copolymer in the toughened engineeringthermoplastic composition may be further compounded with othermaterials, such as other engineering thermoplastics, additives,modifiers, or fillers.

In one embodiment, poly(styrene-block-SBO-block-styrene) (PS-PSBO-PS) orPS-PCSBO-PS is synthesized via RAFT.

The resulting PS-PSBO-PS or PS-PCSBO-PS polymer can contain ≈25 wt %polystyrene and be on the order of 100 kDa.

In one embodiment, PS-PSBO-PS polymers from above embodiment is blendedwith asphalt binders.

As the structure-property relationships for the PS-PSBO-PS system arebuilt, composition and molecular weight ranges that should be bestsuited as bitumen modifiers can be identified from above embodiment.

The developed biopolymers are blended with two asphalts for subsequenttesting. The asphalt binders used are derived from Canadian and Texascrude sources as they are commonly used in the United States. Thebiopolymers are blended at 3% by weight of the combined asphalt binder.A styrene-butadiene type polymer is used as a benchmark polymer for thesubsequent techno-economic analysis. The blending and subsequentrheological testing is outlined in FIG. 3 and follows the AmericanAssociation of State Highway and Transportation Officials (AASHTO) M 320testing for determining the grade of an asphalt binder (AASHTO M 320:Standard Specification for Performance-graded Asphalt Binder. AmericanAssociation of State Highway and Transportation Officials, Washington,D.C. (2002), which is hereby incorporated by reference in its entirety)

Frequency sweeps are carried out in a dynamic shear rheometer (DSR) androtational viscometer (RV) at multiple temperatures. Bending beamrheometer testing is carried out at multiple temperatures. A rollingthin film oven (RTFO) and pressure aging vessel (PAV) are used toconduct simulated aging of the binder blends representing the aging ofbinders that occurs during production of asphalt mixtures and thein-situ aging, respectively.

These tests allow for understanding the effects of polymer content,effects of crude source, and the rheological behavior of the developedblends. Prior to rheological testing, separation testing is done toassess the ability of the polymers to meet American Society for Testingand Materials (ASTM) standards for maintaining homogeneity, ASTM D7173utilizing a rotational viscometer (ASTM Standard C33: Standard Practicefor Determining the Separation Tendency of Polymer from Polymer ModifiedAsphalt. ASTM International, West Conshohocken, Pa. (2003), which ishereby incorporated by reference in its entirety). Each test isconducted in triplicate on the same blends, which allows for analysis ofvariance (ANOVA) and subsequent regression analysis.

Statistical analysis of the data is performed utilizing the chemical andphysical data of the biopolymers and the rheological properties. Theanalysis also includes ANOVA to identify independent variables that aresignificant, e.g. what variables effect the shear modulus of the bindersderived from DSR testing. Once the significant variables are identified,regression analysis can be conducted utilizing the significant variablesto identify interactions between variables and understand their relativemagnitude/effect on the dependent variable. Additional analysis of thedata includes development of binder master curves for comparison ofrheological properties of the binders over a range of temperatures.

Another aspect of the present invention relates to a method of preparinga thermoplastic block copolymer. The method comprises providing aradically polymerizable monomer, represented by A, or a polymer block PAcomprising one or more units of monomer A. A radically polymerizabletriglyceride or mixture thereof, in the form of a plant oil, animal oil,or synthetic triglycerides, represented by B, is also provided. MonomerA or the polymer block PA is polymerized with monomer B via reversibleaddition-fragmentation chain-transfer polymerization (RAFT), in thepresence of a free radical initiator and a chain transfer agent, to formthe thermoplastic block copolymer. The polymerizing step is carried outunder conditions effective to achieve a number average degree ofpolymerization (N_(n)) for the thermoplastic block copolymer of up to100,000 without gelation.

The polymerizing step can be carried out by a) polymerizing monomer Avia RAFT in a solvent suitable for dissolving the PA block; and b)polymerizing monomer B via RAFT in a solvent suitable for dissolving thePA block and a polymer block PB comprising one or more units of monomerB. The PA block from step a) acts as a macro chain transfer agent, whichthe monomer B can add onto, thus forming a diblock copolymer PA-PB. Theresulting di-block copolymer PA-PB from step b) may be used as a macrochain transfer agent to c) further polymerize the di-block PA-PB withmonomer A via RAFT. This adds an additional polymer block to thedi-block copolymer PA-PB, forming a tri-block copolymer PA-PB-PA.

Step c) may be repeated multiple times, adding desired polymer block(either the PA or PB block), to form a desirable multiple blockcopolymer. For instance, a penta-block copolymer PA-PB-PA-PB-PA may beformed by repeating step c) three times, adding PA, PB and PA, in eachstep respectively, to the di-block copolymer PA-PB formed from step b).

Moreover, monomer A or monomer B in the polymering step c) can eachindependently be the same or different monomer than the monomer A ormonomer B used in the polymerizing step a) or b). For instance, whenadding a monomer A to the already formed di-block PA-PB to form atri-block PA-PB-PA, this additional monomer A can be the same kind ofmonomer A unit used in the di-block (e.g., both are styrene), or adifferent kind (e.g., monomer unit A in di-block is styrene; andadditional monomer A is methyl(meth)acrylate).

Using this method, by repeating step c) multiple times, and adding thedesired polymer block each time, different block copolymer architecturesmay be achieved, for instance, multiple block copolymers having a(PA-PB)_(n) architecture or (PA-PB)_(n)-PA architecture, where n is aninteger of greater than 1, are produced; and each monomer A unit ormonomer B unit in architechture may be the same or different

When the chain transfer agent used at starting the polymerization is atelechelic chain transfer agent, the polymerizing step can be carriedout by a) polymerizing monomer A via RAFT in a solvent suitable fordissolving the PA block with the telechelic chain transfer agent,thereby inserting the PA block within the telechelic chain transferagent, yielding a symmetric polymer PA block with a trithiocarbonatelinkage of the telechelic chain transfer agent in the center of thechain contour: PA-TCTA-PA (see Scheme 1); and b) polymerizing monomer Bvia RAFT in a solvent suitable for dissolving the PA block and a polymerblock PB comprising one or more units of monomer B. TCTA is a moiety inthe PA block, derived from the telechelic chain transfer agent, e.g., atrithiocarbonate moiety or any other moiety from a telechelic CTA agentused to produce the telechelic thermoplastic block copolymers. The PAblock (i.e., the PA-TCTA-PA block) from step a) acts as a telechelicmacro chain transfer agent, where the monomer B can symmetrically addinto the interior of the PA block following the same mechanism shown inScheme 1, thus forming a symmetrical triblock copolymer PA-PB-PA (i.e.,PA-PB-TCTA-PB-PA). The resulting tri-block copolymer PA-PB-PA(PA-PB-TCTA-PB-PA) from step b) may be used as a telechelic macro chaintransfer agent to c) further polymerize monomer A into the interiorchain of the tri-block PA-PB-PA symmetrically via RAFT. This addsadditional symmetrical polymer blocks to the interior of the tri-blockcopolymer, forming a penta-block copolymer PA-PB-PA-PB-PA, i.e.PA-PB-PA-TCTA-PA-PB-PA.

Scheme 1. Schematic showing of the basic mechanism of RAFTpolymerization using a telechelic chain transfer agent. AIBN is anexemplary chain initiator, azobisisobutyronitrile; and

is an exemplary monomer unit, a vinyl monomer (Tasdelen et al.,“Telechelic Polymers by Living and Controlled/Living PolymerizationMethods,” Progress in Polymer Science 36 (4), 455-567 (2011), which ishereby incorporated by reference in its entirety).

Moreover, monomer A or monomer B in the polymering step c) can eachindependently be the same or different monomer than the monomer A ormonomer B used in the polymerizing step a) or b). For instance, whenadding a monomer A to the already formed tri-block PA-PB-PA to form apenta-block PA-PB-PA-PB-PA, this additional monomer A can be the samekind of monomer A unit used in the tri-block (e.g., both are styrene),or a different kind (e.g., initially added monomer unit A in tri-blockis styrene (S); and the additional monomer A is methyl(meth)acrylate(MMA), thereby forming PS-PB-PMMA-PB-PS).

Using this method, by repeating step c) multiple times, and adding thedesired symmetrical polymer blocks each time, different block copolymerarchitectures may be achieved, for instance, multiple block copolymershaving a (PA-PB)_(n)-PA architecture or PB-(PA-PB)_(n) architecture,where n is an integer of greater than 2, are produced; and each monomerA unit or monomer B unit in the architecture may be the same ordifferent.

Alternatively, the method of preparing a thermoplastic block copolymercomprises providing a radically polymerizable triglyceride or mixturethereof, in the form of a plant oil, animal oil, or synthetictriglycerides, represented by B, or a polymer block PB comprising one ormore units of monomer B. A radically polymerizable monomer, representedby A, is also provided. Monomer B or the polymer block PB is polymerizedwith monomer A via RAFT, in the presence of a free radical initiator anda chain transfer agent, to form the thermoplastic block copolymer. Thepolymerizing step is carried out under conditions effective to achieve anumber average degree of polymerization (N_(n)) for the thermoplasticblock copolymer of up to 100,000 without gelation.

The polymerizing step can be carried out by a) polymerizing monomer Bvia RAFT in a solvent suitable for dissolving the PB block; and b)polymerizing monomer A via RAFT in a solvent suitable for dissolving apolymer block PA comprising one or more units of monomer A and the PBblock. The PB block from step a) acts a macro chain transfer agent,which the monomer B can add onto, thus forming a diblock copolymerPB-PA. The resulting di-block copolymer PB-PA from step b) may be usedas a macro chain transfer agent to c) further polymerize the di-blockPB-PA with monomer B via RAFT. This adds an additional polymer block tothe di-block copolymer PB-PA, forming a tri-block copolymer PB-PA-PB.

Step c) may be repeated multiple times, adding desired polymer block(either the PB or PA block), to form a desirable multiple blockcopolymer. For instance, a penta-block copolymer PB-PA-PB-PA-PB may beformed by repeating step c) three times, adding PB, PA, and PB, in eachstep respectively, to the di-block copolymer PB-PA formed from step b).

Moreover, monomer A or monomer B in the polymering step c) can eachindependently be the same or different monomer than the monomer A ormonomer B used in the polymerizing step a) or b). For instance, whenadding a monomer B to the already formed di-block PB-PA to form atri-block PB-PA-PB, this additional monomer B can be the same kind ofmonomer B unit used in the di-block (e.g., both are soybean oilcontaining triglycerides with the same conjugation site and the samedegree of conjugation), or a different kind (e.g., monomer unit B indi-block is soybean oil; and additional monomer B is a different type ofplant oil or animal oil, or soybean oil having triglycerides withdifferent conjugation site and different degree of conjugation).

Using this method, by repeating step c) multiple times, and adding thedesired polymer block each time, different block copolymer architecturesmay be achieved, for instance, multiple block copolymers having aPB-(PA-PB)_(n) architecture, where n is an integer of greater than 1,are produced; and each monomer A unit or monomer B unit in architecturemay be the same or different.

When the chain transfer agent used at starting the polymerization is atelechelic chain transfer agent, the polymerizing step can be carriedout by a) polymerizing monomer B via RAFT in a solvent suitable fordissolving the PB block with the telechelic chain transfer agent,thereby inserting the PA block within the telechelic chain transferagent, yielding a symmetric polymer PB block with a trithiocarbonatelinkage of the telechelic chain transfer agent in the center of thechain contour: PB-TCTA-PB (see Scheme 1); and b) polymerizing monomer Avia RAFT in a solvent suitable for dissolving a polymer block PAcomprising one or more units of monomer A and the PB block. TCTA is amoiety in the PB block, derived from the telechelic chain transferagent, e.g., a trithiocarbonate moiety or any other moiety from atelechelic CTA agent used to produce the telechelic thermoplastic blockcopolymers. The PB block (i.e., the PB-TCTA-PB block) from step a) actsas a telechelic macro chain transfer agent, where the monomer A cansymmetrically add into the interior of the PB block following the samemechanism shown in Scheme 1, thus forming a symmetrical triblockcopolymer PB-PA-PB (i.e., PB-PA-TCTA-PA-PB). The resulting tri-blockcopolymer PB-PA-PB (PB-PA-TCTA-PA-PB) from step b) may be used as atelechelic macro chain transfer agent to c) further polymerize monomer Binto the interior chain of the tri-block PB-PA-PB symmetrically viaRAFT. This adds additional symmetrical polymer blocks into the interiorof the tri-block copolymer, forming a penta-block copolymerPB-PA-PB-PA-PB, i.e., PB-PA-PB-TCTA-PB-PA-PB.

Moreover, monomer A or monomer B in the polymering step c) can eachindependently be the same or different monomer than the monomer A ormonomer B used in the polymerizing step a) or b). For instance, whenadding a monomer B to the already formed tri-block PB-PA-PB to form apenta-block PB-PA-PB-PA-PB, this additional monomer B can be the samekind of monomer B unit used in the tri-block (e.g., both are soybean oilcontaining triglycerides with the same conjugation site and the samedegree of conjugation), or a different kind (e.g., initially addedmonomer unit B in tri-block is soybean oil (SBO); and the additionalmonomer B is a different type of plant oil, animal oil, or synthetictriglycerides; or triglycerides or triglyceride mixtures with differentconjugation site and different degree of conjugation (B₂), therebyforming PSBO-PA-PB₂—PA-PSBO).

Using this method, by repeating step c) multiple times, and adding thedesired symmetrical polymer blocks each time, different block copolymerarchitectures may be achieved, for instance, multiple block copolymershaving a (PA-PB)_(n)-PA architecture or PB-(PA-PB)_(n) architecture,where n is an integer of greater than 2, are produced; and each monomerA unit or monomer B unit in the architecture may be the same ordifferent.

Another aspect of the present invention relates to a method of preparinga thermoplastic homopolymer. The method comprises providing a radicallypolymerizable triglyceride or mixture thereof, in the form of a plantoil, animal oil, or synthetic triglycerides. This triglyceride-basedmonomer is then polymerized via RAFT, in the presence of a free radicalinitiator and a chain transfer agent, to form the thermoplastichomopolymer. The polymerizing step is carried out under conditionseffective to achieve a number average degree of polymerization (N_(n))for the thermoplastic homopolymer of up to 100,000 without gelation. Theembodiments for the starting material (polymerizable triglyceride ormixtures of triglycerides), the reaction agents, the reaction mechanism,and the reaction conditions and parameters are the same as thosedescribed for methods of preparing a thermoplastic block copolymer byusing either a regular chain transfer agent or a telechelic chaintransfer agent.

The resulting thermoplastic homopolymer can itself be used as athermoplastic elastomer, and has the same monomer unit, structures, andcharacteristics as the PB block described in the embodiments for thethermoplastic block copolymers. Accordingly, this thermoplastichomopolymer can also be used as a polymer block, and can be furtherpolymerized with other monomers or form a polymerized plan oil- oranimal oil-based thermoplastic block copolymer.

Another aspect of the present invention relates to a method of preparinga thermoplastic statistical copolymer. The method comprises providing aradically polymerizable monomer, represented by A. A radicallypolymerizable triglyceride or mixture thereof, in the form of a plantoil, animal oil, or synthetic triglycerides, represented by B is alsoprovided. Monomer A and monomer B are simultaneously polymerized, viaRAFT, in the presence of a free radical initiator and a chain transferagent to form the thermoplastic statistical copolymer. The polymerizingstep is carried out under conditions effective to achieve a numberaverage degree of polymerization (N_(n)) for the thermoplasticstatistical copolymer of up to 100,000 without gelation.

The method can be used to simultaneously polymerize three or moredifferent monomer units. For instance, another radically polymerizablemonomer, represented by C can also be provided, in addition to monomer Aand monomer C. Monomer C is different than monomer A or monomer B.Monomer A, monomer B, and monomer C are then polymerized simultaneously,via RAFT, in the presence of the free radical initiator and the chaintransfer agent to form the thermoplastic statistical copolymer. Thepolymerizing step is carried out under conditions effective to achieve anumber average degree of polymerization (N_(n)) for the thermoplasticstatistical copolymer of up to 100,000 without gelation.

The polymerization of monomers A and B to form thermoplastic blockcopolymer or thermoplastic statistical copolymer is performed throughliving free radical polymerization which involves living/controlledpolymerization with free radical as the active polymer chain end (Moadet al., “The Chemistry of Radical Polymerization—Second Fully RevisedEdition,” Elsevier Science Ltd. (2006), which is hereby incorporated byreference in its entirety). This form of polymerization is a form ofaddition polymerization where the ability of a growing polymer chain toterminate has been removed. The rate of chain initiation is thus muchlarger than the rate of chain propagation. The result is that thepolymer chains grow at a more constant rate than seen in traditionalchain polymerization and their lengths remain very similar. One form ofliving free radical polymerization is Radical Addition-FragmentationChain Transfer (RAFT).

Radical Addition-Fragmentation Chain Transfer (RAFT) polymerization is atype of living polymerization or controlled polymerization, utilizing achain transfer agent (CTA). Conventional RAFT polymerization mechanism,consisting of a sequence of addition-fragmentation equilibria, is shownin FIG. 1 (Moad et al., “Living Radical Polymerization by the RaftProcess—a First Update,” Australian Journal of Chemistry 59: 669-92(2006), which is incorporated herein by reference in its entirety). Asshown in FIG. 1, the RAFT polymerization reaction starts withinitiation. Initiation is accomplished by adding an agent capable ofdecomposing to form free radicals; the decomposed free radical fragmentof the initiator attacks a monomer yielding a propagating radical (P^(•)_(n)), in which additional monomers are added producing a growingpolymer chain. In the propagation step, the propagating radical (P^(•)_(n)) adds to a chain transfer agent (CTA), such as a thiocarbonylthiocompound (RSC(Z)=S, 1), followed by the fragmentation of theintermediate radical (2) forming a dormant polymer chain with athiocarbonylthio ending (P_(n)S(Z)C=S, 3) and a new radical (R^(•)).This radical (R^(•)) reacts with a new monomer molecule forming a newpropagating radical (P^(•) _(m)). In the chain propagation step, (P^(•)_(n)) and (P^(•) _(m)) reach equilibrium and the dormant polymer chain(3) provides an equal probability to all polymers chains to grow at thesame rate, allowing polymers to be synthesized with narrowpolydispersity. Termination is limited in RAFT, and, if occurring, isnegligible. Targeting a specific molecular weight in RAFT can becalculated by multiplying the ratio of monomer consumed to theconcentration of CTA used by the molecular weight of the monomer.

The initiating agents often are referred to as “initiators.” Suitableinitiators depend greatly on the details of the polymerization,including the types of monomers being used, the type of catalyst system,the solvent system, and the reaction conditions. A typical radicalinitiator can be azo compounds, which provide a two-carbon centeredradical. Radical initiators such as benzoyl peroxide,azobisisobutyronitrile (AIBN), 1,1′ azobis(cyclohexanecarbonitrile) or(ABCN), or 4,4′-Azobis(4-cyanovaleric acid) (ACVA); redox initiator suchas benzoyl peroxide/N,N-dimethylaniline; microwave heating initiator;photoinitiator such as (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide;gamma radiation initiator; or lewis acids such as scandium(III) triflateor yttrium (III) triflate, are typically used in RAFT polymerization.

RAFT polymerization can use a wide variety of CTA agents. Suitable CTAagents should be capable of initiating the polymerization of themonomers (styrene and AESO) and achieve a narrow polydispersity in theprocess. For a RAFT polymerization to be efficient, the initial CTAagents and the polymer RAFT agent should have a reactive C═S doublebond; the intermediate radical should fragment rapidly without sidereactions; the intermediate should partition in favor of products, andthe expelled radicals (R^(•)) should efficiently re-initiatepolymerization. Suitable CTA agent is typically a thiocarbonylthiocompound (ZC(═S)SR:

where R is free radical leaving group and Z is a group that modifiesaddition and fragmentation rates of RAFT polymerization. Exemplary CTAagents include, but are not limited to, a dithioester compound (whereZ=aryl, heteraryl, or alkyl), a trithiocarbonate compound (whereZ=alkylthio, arylthio, or heteroarylthio), a dithiocarbamate comound(where Z=arylamine or heterarylamine or alkylamine), and a xantatecompound (where Z=alkoxy, aryloxy, or heteroaryloxy), that are capableor reversible association with polymerizable free radicals. Z can alsobe sulfonyl, phosphonate, or phosphine. A more extensive list ofsuitable CTA agents (or RAFT agents) can be found in Moad et al.,“Living Radical Polymerization by the Raft Process—a First Update,”Australian Journal of Chemistry 59: 669-92 (2006); Moad et al., “LivingRadical Polymerization by the Raft Process—a Second Update,” AustralianJournal of Chemistry 62(11):1402-72 (2009); Moad et al., “Living RadicalPolymerization by the Raft Process—a Third Update,” Australian Journalof Chemistry 65: 985-1076 (2012); Skey et al., “Facile one pot synthesisof a range of reversible addition-fragmentation chain transfer (RAFT)agents.” Chemical Communications 35: 4183-85 (2008), which are herebyincorporated by reference in their entirety. Effectiveness of the CTAagent depends on the monomer being used and is determined by theproperties of the free radical leaving group R and the Z group. Thesegroups activate and deactivate the thiocarbonyl double bond of the RAFTagent and modify the stability of the intermediate radicals (Moad etal., “Living Radical Polymerization by the Raft Process—a SecondUpdate,” Australian Journal of Chemistry 62(11):1402-72 (2009), which ishereby incorporated by reference in its entirety). Typical CTA agentsused are 1-phenylethyl benzodithioate or 1-phenylethyl2-phenylpropanedithioate.

In one embodiment, the chain transfer agent used is a telechelic chaintransfer agent, which typically is based on trithiocarbonatefunctionality. Polymers produced from the chain transfer agent based ontrithiocarbonate functional group retain the CTA functionality in thestatistical center of the chain, as opposed to polymers produced by adithiocarbonate-based CTA, which retain the CTA functionality at the endof the polymeric chain. The telechelic chain transfer agent is capableof adding polymer blocks symmetrically from the interior where thetrithiocarbonate functionality is located, i.e., polymerizing monomersfrom both ends, forming symmetrical architecture or polymer blocks. Forexample, the RAFT process begins with the chain transfer of a growing Aradical to a functional trithiocarbonate:

The formed radical intermediate is stable against coupling ordisproportion reactions with other free radicals. One of the thioategroups reversibly fragments allowing propagation of one of the threearms:

See also Scheme 1 for the basic mechanism of RAFT polymerization using atelechelic chain transfer agent. Suitable telechelic CTA agents includeany trithiocarbonate compound (e.g.,

where Z=alkylthio, arylthio, or heteroarylthio and R is free radicalleaving group). A more extensive list of suitable telechelic CTA agents(trithiocarbonate compounds) can be found in Skey et al., “Facile onepot synthesis of a range of reversible addition-fragmentation chaintransfer (RAFT) agents.” Chemical Communications 35: 4183-85 (2008),which is hereby incorporated by reference in its entirety. A typicaltelechelic chain transfer agent is dibenzyl carbonotrithioate

The radically polymerizable monomers used in this method include, butare not limited to, a vinyl, acrylic, diolefin, nitrile, dinitrile,acrylonitrile monomer, a monomer with reactive functionality, acrosslinking monomer, and mixtures thereof. The exemplary embodimentsfor the monomer A in accordance with the method of the present inventionhave been described above in the exemplary embodiments for the monomer Ain the thermoplastic block copolymer. Exemplary radically polymerizablemonomers A used in this method are styrene, α-methyl styrene, t-butylstyrene, vinyl xylene, vinyl naphthalene, vinyl pyridine, divinylbenzene, vinyl acetate, N-vinylpyrrolidone, methyl acrylate, C₁-C₆(meth)acrylate (i.e., methyl methacrylate, ethyl methacrylate, propyl(meth)acrylate, butyl (meth)acrylate, heptyl (meth)acrylate, or hexyl(meth)acrylate), acrylonitrile, adiponitrile, methacrylonitrile,butadiene, isoprene, or mixtures thereof. In one embodiment, thepolymerizable vinyl monomer A is a vinyl aromatic monomer, for instance,a styrene. In one embodiment, the polymerizable monomer A is an acrylatemonomer, for instance, a methyl (meth)acrylate.

The radically polymerizable plant oil monomers or animal oil monomersused in this method include, but are not limited to, the monomer fromvegetable oils such as soybean oil, peanut oil, walnut oil, palm oil,palm kernel oil, sesame oil, sunflower oil, safflower oil, rapeseed oil,linseed oil, flax seed oil, colza oil, coconut oil, corn oil, cottonseedoil, olive oil, castor oil, false flax oil, hemp oil, mustard oil,radish oil, ramtil oil, rice bran oil, salicornia oil, tigernut oil,tung oil, etc., and mixtures thereof. Exemplary plant oils used in themethod are soybean oil, corn oil, linseed oil, flax seed oil, orrapeseed oil. In one embodiment, the polymerized plant oil monomer ispoly(soybean oil). Suitable animal fats used in accordance with thepresent invention include, but are not limited to, beef or mutton fatsuch as beef tallow or mutton tallow, pork fat such as pork lard,poultry fat such as turkey and/or chicken fat, and fish fat/oil. Theanimal fats can be obtained from any suitable source includingrestaurants and meat production facilities. The triglyceride in theplant oil or animal oil can comprise one or more conjugated sites, asdescribed above. In one embodiment, the triglyceride is an acrylatedepoxidized triglyceride.

Accordingly, in one embodiment, the present invention relates to methodsof making a thermoplastic and elastomeric block copolymer having apoly(styrene-soybean oil) (PS-PSBO) diblock copolymer architecture or apoly(styrene-soybean oil-styrene) (PS-PSBO-PS) triblock polymerarchitecture, via RAFT reaction. The method comprises the followingsteps: a) RAFT polymerization of styrene homopolymer (PS), to reach amolecular weight of 1 to 1000 kDa, 1 to 300 kDa, or 10 to 30 kDa,optionally followed by purification; b) RAFT polymerization of SBO orCSBO using PS as a macro chain transfer agent, in a solvent suitable forthe mutual dissolution of PS and polySBO or polyCSBO, to yield thediblock copolymer PS-PSBO or PS-PCSBO having a molecular weight of 5 to10,000 kDa, 5 to 500 kDa, 15 to 300 kDa, 40 to 100 kDa, or 80 to 100kDa; and c) optionally RAFT polymerization of styrene using PS-PSBO orPS-PCSBO as the macrochain transfer agent, to yield triblock copolymerPS-PSBO-PS or PS-PCSBO-PS having a molecular weight of 7 to 10,000 kDa,7 to 1000 kDa, 7 to 500 kDa, 15 to 350 kDa, 80 to 120 kDa or 100 to 120kDa.

Alternatively, the method of the present invention may comprise thefollowing steps: a) RAFT polymerization of SBO or CSBO to reach amolecular weight of 1 to 1000 kDa, 1 to 300 kDa, or 10 to 30 kDa,optionally followed by purification; b) RAFT polymerization of styrenehomopolymer (PS), using PSBO or PCSBO as a macrochain transfer agent, ina solvent suitable for the mutual dissolution of PS and PSBO or PCSBO,to yield the diblock copolymer PS-PSBO or PS-PCSBO having a molecularweight of 5 to 10,000 kDa, 5 to 500 kDa, 15 to 300 kDa, 40 to 100 kDa,or 80 to 100 kDa; and c) optionally RAFT polymerization of styrene tothe end of PSBO or PCSBO using PS-PSBO or PS-PCSBO as the macrochaintransfer agent, to yield triblock copolymer PS-PSBO-PS or PS-PCSBO-PShaving a molecular weight of 7 to 10,000 kDa, 7 to 1000 kDa, 7 to 500kDa, 15 to 350 kDa, 80 to 120 kDa or 100 to 120 kDa.

In one embodiment, the method of the present invention may also comprisethe following steps: a) RAFT polymerization of styrene homopolymer usinga telechelic chain transfer agent to reach a molecular weight of 1 to1000 kDa, 1 to 300 kDa, or 10 to 30 kDa, optionally followed bypurification; b) RAFT polymerization of PSBO or PCSBO, using the styrenehomopolymer (PS) as the macro chain transfer agent, in a solventsuitable for the mutual dissolution of PS and PSBO or PCSBO, to yield atriblock PS-PSBO-PS or PS-PCSBO-PS having a molecular weight of 7 to10,000 kDa, 7 to 1000 kDa, 7 to 500 kDa, 15 to 350 kDa, 80 to 120 kDa or100 to 120 kDa.

A typical conjugated plant oil or animal oil used in accordance with themethod of the present invention is acrylated epoxidized plant oil oranimal oil, such as acrylated epoxidized soybean oil, which contains oneor more acrylated epoxidized triglycerides.

In RAFT polymerization, reaction time, temperature, and solventconcentration should be chosen appropriately to ensure the production ofnon-crosslinked thermoplastic elastomers. Reaction time relates closelyto the temperature the reaction is carried out at: higher temperaturerequires shorter reaction times and lower temperature requires longerreaction times. Monitoring the time of the polymerization of the AESOblock is crucial as reacting the vegetable oil too long causes thepolymer to crosslink; whereas reacting the vegetable oil for too short atime period causes polymer conversion to be too slow. Temperatures forthe RAFT polymerization on plant oil or animal oil reaction can rangefrom room temperature to up to 180° C.

A RAFT reaction of styrene and soybean oil to prepare thermoplasticelastomers, polymerization can be carried out at a temperature of 200°C. or lower. The optimal temperature is the minimum at whichpolymerization can occur over reasonable time scales, e.g., 6-48 hours.In a RAFT reaction of SBO or CSBO to make PSBO- or PCSBO-basedthermoplastic elastomers, it is desirable to produce PSBO or PCSBO withhigh molecular weight and low glass transition temperature (T_(g)), andwith the retention of the terminal halogen, which allows the subsequentaddition of a polystyrene block. Thus, high reaction temperatures as inconventional radical polymerizations are undesirable in a RAFT reactioninvolving SBO or CSBO. Typical reaction temperatures for a RAFT reactionbetween styrene and soybean oil is 150° C. or lower, for instance, from0 to 150° C., from 40° C. to 150° C., from 80° C. to 150° C., from 40°C. to 100° C., from 50° C. to 85° C., or from 0° C. to 50° C.

In a conventional RAFT polymerization process, a N:1 molar ratio(monomer to CTA ratio) would yield polymers with an average of N repeatunits where the ratio of monomer to CTA agent usually goes from 1000:1down to 1:1. In the RAFT reaction of plant oil or animal oil of thepresent intention, however, a 10:1 molar ratio of monomer to CTA isused, to obtain a thermoplastic elastomer. This monomer to CTA ratiorepresents an excess of CTA compared to a conventional RAFT synthesis.In AESO polymerization, however, the multifunctional character of themonomer tends towards crosslinking. This crosslinking can be mitigatedby the use of excess CTA.

In one embodiment, RAFT polymerization is carried out at a molar ratioof the chain transfer agent to the monomer ranging from 1:1 to 50:1.

Solvent is selected based the requirements of mutual polySBO/polystyrenesolubility and a normal boiling point compatible with the polymerizationtemperature. The solvent used in the RAFT polymerization of styrene andsoybean oil may be toluene, dioxane, THF, chloroform, cyclohexane,dimethyl sulfoxide, dimethyl formamide, acetone, acetonitrile,n-butanol, n-pentanol, chlorobenzene, dichloromethane, diethylether,tert-butanol, 1,2,-di chloroethylene, diisopropylether, ethanol,ethylacetate, ethylmethylketone, heptane, hexane, isopropylalcohol,isoamylalcohol, methanol, pentane, n-propylacohol, pentachloroethane,1,1,2,2,-tetrachloroethane, 1,1,1,-trichloroethane, tetrachloroethylene,tetrachloromethane, trichloroethylene, water, xylene, benzene,nitromethane, or a mixture thereof. The typical solvent used for ATRP ofstyrene and soybean oil is dioxane. Monomer concentrations in thereactions depend partially on the solubility of the monomer and thepolymer products as well as the evaporation temperature of the solvent.Solvent concentration can affect the gelation of the polymer. Inconventional RAFT, monomer concentration in solvent duringpolymerizations can range from 100 wt % (no solvent) to 33.3 wt %.However, insufficient solvent in the RAFT reaction can cause the polymerto crosslink in a shorter time period without ever reaching high enoughconversions. Therefore, solvent is typically added in excess to allowthe polymer chains to grow and obtain a conversion rate to 80% withoutrisk of the polymer reaching the gel point. The concentration ofmonomers dissolved in the solvent in the RAFT reactions may range from5% to 100% weight percentage monomer. Typically, a monomer concentrationof less than 40% by mass is suitable to ensure the solubility of theresulting polymers and additionally to prevent premature gelation.

In one embodiment, the method is carried out in the presence of asolvent, at a temperature ranging from 50 to 85° C. The monomer Bconcentration in the solvent can range from 5% to 100 wt %, forinstance, from 10% to 40 wt %.

After the radical polymerization, the polymerized plant oil- or animaloil-based block copolymer may be further catalytically hydrogenated topartially or fully saturate the plant oil block or animal oil block.This process removes reactive unsaturation from the rubbery component,yielding improved resistance to oxidative degradation, reducedcrosslinkability and increased resistance to chemical attack. Moreover,hydrogenation precludes gelation on subsequent block additions.

RAFT experiments can be carried out by varying the following parameters.

Temperature

Conventional free radical polymerization (CFRP) of CSBO has beenreported at temperatures ranging from 60-150° C. In CFRP, thetemperature dependence on polymerization kinetics is dominated by thedecomposition reaction of the initiator. The trade-off of the hightemperature is a higher polymerization rate with lower molecular weightand increased chain transfer reactions. Increasing chain transferreaction is desirable in the production of thermoset polymers, where thepolySBO eventually gels and solidifies as chains begin to crosslink(Valverde et al., “Conjugated Low-Saturation Soybean Oil Thermosets:Free-Radical Copolymerization with Dicyclopentadiene andDivinylbenzene,” Journal of Applied Polymer Science 107:423-430 (2008);Robertson et al., “Toughening of Polylactide with Polymerized SoybeanOil,” Macromolecules 43:1807-1814 (2010), which are hereby incorporatedby reference in their entirety).

For the method of preparing CSBO-based thermoplastic elastomers, theoptimal temperature is the minimum at which polymerization can occurover reasonable time scales, e.g., 1-48 hours. In contrast toconventional free radical polymerization, the primary role oftemperature in a RAFT reaction is to shift the equilibrium towardshigher free radical concentration and to increase the propagation rate.These are desirable to a certain extent; however, as the free radicalconcentration increases so does the rate of termination and transferreactions. In RAFT of CSBO to make PCSBO-based thermoplastic elastomers,it is desirable to produce PCSBO with a high molecular weight and a lowglass transition temperature (T_(g)), and with the retention of theterminal halogen, which allow the subsequent addition of a polystyreneblock. Thus, the increased rate of termination and transfer reactions(i.e., high reaction temperature) are undesirable in ATRP of CSBO.

Solvent

Bulk polymerization is the starting point as the solvent directly placeslimits on the polymerization temperature and also influences the RAFTequilibrium. The synthesis of polySBO from a polystyrene macroinitiatorrequires a solvent. Solvent is selected based the requirements of mutualpolySBO/polystyrene solubility and a normal boiling point compatiblewith the polymerization temperature.

Time

Reactions are allowed to progress for 12 hours, and gel permeationchromatography is used to assess the degree of polymerization. Thepolymerization kinetics are subsequently assessed and the parameters arefine-tuned such that polySBO compounds can be reproducibly made withminimal polydispersity and of targeted molecular weight. Differentialscanning calorimetry is used to assess the T_(g) of the polySBOmaterials, which is expected to be on the order of −50° C. (Yang et al.,“Conjugation of Soybean Oil and It's Free-Radical Copolymerization withAcrylonitrile,” Journal of Polymers and the Environment 1-7 (2010);Robertson et al., “Toughening of Polylactide with Polymerized SoybeanOil,” Macromolecules 43:1807-1814 (2010), which are hereby incorporatedby reference in their entirety).

EXAMPLES

The following examples are for illustrative purposes only and are notintended to limit, in any way, the scope of the present invention.

Example 1—Synthesis of Poly(Styrene) (PS), Poly(Acrylated EpoxidizedSoybean Oil) (PAESO), Poly(Acrylated Epoxidized SoybeanOil-Block-Styrene) (PAESO-PS), and Poly(Styrene-Block-AcrylatedEpoxidized Soybean Oil-Block-Styrene) (PS-PAESO-PS) Via ReversibleAddition-Fragmentation Chain Transfer Polymerization (RAFT)

Acrylated Epoxidized Soy Bean Oil (AESO) was purchased from FisherScientific and was used as received. High-performance liquidchromatography (HPLC)-grade toluene was purchased from Fisher Scientificand used without further purification. Styrene was purchased from FisherScientific and purified over basic alumina followed by threefreeze-pump-thaw cycles. RAFT synthesis was performed in a similarmanner to the procedure described in Moad et al., “Living RadicalPolymerization by the Raft Process—a First Update,” Australian Journalof Chemistry 59: 669-92 (2006); Moad et al., “Living RadicalPolymerization by the Raft Process—a Second Update,” Australian Journalof Chemistry 62(11):1402-72 (2009), which are hereby incorporated byreference in their entirety. Briefly, azobisisobutyronitrile (AIBN, asshown in FIG. 4) was used as the initiator. 1-phenylethyl benzodithioate(as shown in FIG. 5) was used as the chain transfer agent (CTA), and wassynthesized according to established procedures.

Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT)of Styrene

Monomer (styrene), initiator, CTA, and solvent were mixed under argon ina round-bottomed flask with various mass ratios of monomer: solvent, 1:5molar ratio of initiator to CTA, and 10:1 molar ratio of monomer to CTA.The reaction flask was bubbled with argon for 30 minutes to removeoxygen from the system before the temperature was increased. Thereaction was run at 100° C. and the reaction time varied according thedesired molecular weight (Mn). The molecular weight (number average)increase of the styrene homopolymer as a function of time is shown inFIG. 6.

RAFT of Acrylated Epoxidized Soybean Oil

Monomer (AESO), initiator, CTA, and solvent (1,2-dioxane) were mixedunder argon in a 100 mL round-bottomed flask with various mass ratios ofmonomer: solvent, 1:5 molar ratio of initiator to CTA, and 10:1 molarratio of monomer to CTA. This monomer to CTA ratio represents an excessof CTA compared to a typical RAFT synthesis. In a typical RAFT reaction,a N:1 ratio would yield polymers with an average of N repeat units. InRAFT polymerization of AESO, however, the multifunctional character ofthe AESO monomer tends to crosslink, which is mitigated by the use ofexcess CTA, as described herein. The reaction flask was bubbled withargon for 30 minutes to remove oxygen from the system before thetemperature was increased. The reaction was run at 70° C. and thereaction time varied according the desired molecular weight (Mn).

Synthesis of P(Styrene-B-AESO)

For synthesis of P(styrene-b-AESO), AESO monomer dissolved in toluene(or dioxane) was transferred to the reaction vessel containing thestyrene homopolymer. The reaction proceeded for 5-6 hours, and theproduct was cooled down and precipitated three times in excess methanoland water. Mn was monitored as a function of time for the diblockcopolymer (FIG. 7). The product was stirred in a 2:1 volume ratio ofmethanol to ethanol solution to remove unreacted AESO monomer. The finalproduct (FIG. 8) was vacuum dried for 24 hours at room temperature. FIG.9 shows the increase in molecular weight from the monomer to thehomopolymer, and to the diblock copolymer.

Synthesis of P(Styrene-B-AESO-B-Styrene)

For P(styrene-b-AESO-b-styrene), the P(styrene-b-AESO) diblock wasredissolved in toluene (or dioxane), styrene, and AIBN. The reactionvessel was bubbled with argon for 1 hour and the reaction proceeded for1-2 hours at 70° C. The final product was precipitated two times inexcess methanol and water. The product was then stirred in a 2:1 volumeratio of methanol to ethanol solution for 15 minutes to remove theunreacted AESO monomer. The product was filtered and vacuum dried atroom temperature for 24 hours (FIG. 10).

Reaction Time

RAFT reaction times were varied according the desired molecular weightMn. See FIG. 7. Most reactions were stopped after 24 hours. Mn ofpoly(styrene-b-AESO) was also monitored as a function of time, as shownin FIG. 6. FIG. 9 shows the gel permeation chromatography (GPC) curve,in which a decrease in elution time (increase in molecular weight) fromthe monomer, to homopolymer, to the diblock can be seen. After theaddition of the final styrene block, the final productp(styrene-b-AESO-b-styrene) was subjected to different characterizationtechniques.

Characterizations of the Polymers

¹H-NMR was performed to prove the presence of polystyrene and to showthe percentage of polystyrene in the product. The results show a 22.4%styrene content in the product. See FIG. 11.

Differential scanning calorimetry (DSC) showed a glass transitiontemperature for the PAESO at −10° C.; no apparent glass transition ispresent for the polystyrene block. See FIG. 12,

Isothermal frequency scans with a frequency ranging 0.1-100 rad/s wereconducted within the linear viscoelastic regime using a strain of 2.5%.The initial temperature was set to 120° C., and the final temperaturewas set to 220° C. Temperature was changed in 20° C. decrements,allowing 3 minutes as an equilibration time. The elastic modulus, G″,shows no apparent change with change in frequency or temperatures belowabout 200° C. The rheology result is shown in FIG. 13.

Tensile testing was performed in an Instron 5569 using a speed of 60mm/minute (FIG. 14). The results show that the maximum stress that canbe applied to the RAFT synthesized triblock copolymer was about 1.3 MPa(FIG. 15).

Example 2—Synthesis and Characterization of PAESO, PAESO-PS, PS-PAESO,and PS-PAESO-PS Via RAFT Polymerization

Materials, synthetic procedures, and characterization experimentationsfor PAESO, PAESO-PS, PS-PAESO, and PS-AESO-PS via RAFT polymerizationhave been described in Example 1. The polymers synthesized andsubsequently used for characterizations are listed in Table 2. Theresults are shown in FIGS. 16-18.

TABLE 2 List of polymers used for characterizations Sample Name M.W.^(a)PDI^(b) % Sty ^(c) 1^(st d) 2^(nd e) PAESO 29,500 1.39 0 — — PAESO-PS48,150 1.59 0.39 18,650 — PS-PAESO 40,980 1.34 0.33 13,900 — PS-PAESO-PS#1 53,300 1.84 0.49 13,900 12,200 ^(a)Total molecular weight of BCP^(b)Polydispersity ^(c) Percent styrene in BCP ^(d) Molecular weight ofstyrene in first block ^(e) Molecular weight of styrene in second block

Example 3—Synthesis and Characterization of Poly(Acrylated EpoxidizedCorn Oil) (PAECO) Homopolymers Via RAFT Polymerization

Materials, synthetic procedures, and characterization experimentationsfor PAECO homopolymer via RAFT polymerization are the same as thosedescribed in Example 1, except that the monomer used in the RAFTpolymerization in this example is corn oil rather than soybean oil. Theresults are shown in FIG. 19-20.

Example 4—Synthesis and Characterization of PS-PAESO-PS and PS-PAECO-PSTriblock Copolymers Using Telechelic Chain Transfer Agent Via RAFTPolymerization

Monomer (styrene), initiator, telechelic CTA, and solvent were mixedunder argon in a round-bottomed flask with various mass ratios ofmonomer: solvent, 1:5 molar ratio of initiator to CTA, and 10:1 molarratio of monomer to CTA. The reaction flask was bubbled with argon for30 minutes to remove oxygen from the system before the temperature wasincreased. The reaction was run at 100° C. and the reaction time variedaccording the desired molecular weight (Mn).

For P(styrene-b-AESO-b-styrene) or P(styrene-b-AECO-b-styrene) triblock,polystyrene homopolymer was redissolved in toluene (or dioxane), AESO(or AECO), and AIBN. The reaction vessel was bubbled with argon for 1hour and the reaction proceeded for 4-6 hours at 70° C. The finalproduct was precipitated two times in excess methanol and water. Theproduct was then stirred in a 2:1 volume ratio of methanol to ethanolsolution for 15 minutes to remove the unreacted AESO monomer.

Characterization experimentations for the PS-PAESO-PS and PS-PAECO-PSblock copolymer via the RAFT polymerization are otherwise the same asdescribed in Examples 1-2. The results are shown in FIG. 21-23.

Example 5—Synthesis and Characterization of Statistical Copolymer fromAESO Monomer or AECO Monomer Via RAFT Polymerization

Materials and characterization experimentations for the RAFTpolymerization have been described in Examples 1 and 3. The syntheticprocedures and the RAFT agents are otherwise the same as those describedin Examples 1 and 3, except that a statistical copolymer was synthesizedby simultaneous polymerization of the styrene monomer and the AESO/AECOmonomer via RAFT polymerization. The results are shown in FIG. 24-25.

Example 6—Post-Polymerization Modification ofP(Styrene-b-AESO-b-Styrene)

After the different p(styrene-b-AESO-b-Styrene) triblocks weresynthetized, the polymers were redissolved in solvent, and Cu_(II)Cl₂was added (0.1% by mass of Cu_(II)Cl₂ to polymer to) to the solution.This procedure changed the polymer chain ends from a CTA functionalgroup-terminated group to a halogen-terminated group, which furtherimproves its chemical interactions when the polymers are mixed with anasphalt or other additives: P•+XS Cu_(II)Cl₂→PCl+Cu_(I)Cl.

Example 7—Asphalt Modification with Biopolymers Derived from RAFTPolymerization of Soybean Oil

Kraton® D1101, an SBS polymer, is commonly blended with liquid asphalt,at two to five percent polymer by weight of asphalt, to enhance theproperties of asphalt pavements. Modifying asphalt with Kraton®increases its stiffness and elasticity at high temperatures whichimproves an asphalt pavement's resistance to rutting caused by trafficloading at high temperatures. A material that stiffens asphalt at hightemperatures would typically stiffen asphalt at low temperatures,thereby, increasing an asphalt pavement's susceptibility to lowtemperature cracking. However, due to the rubbery properties of Kraton®,modifying asphalt with Kraton® does not generally affect the crackingsusceptibility of asphalt at low temperatures. Therefore, Kraton®essentially widens the temperature range in which an asphalt pavementwill adequately perform.

Paving grade liquid asphalt is most commonly bought and sold in theUnited States using the Performance Grade (PG) specification. PGspecifications grade liquid asphalt with two numbers, a high temperaturegrade and a low temperature grade. These grades correspond to thetemperature in degrees Celsius that the asphalt will adequately performin a pavement. An example grade is a PG 64-22. The first number, 64, isthe high temperature grade. This means the asphalt possesses adequatephysical properties up to at least 64° C. The higher the hightemperature PG of liquid asphalt is, the greater resistance it will haveto rutting in an asphalt pavement. The second number, −22, is the lowtemperature grade and means the asphalt possesses low enough creepstiffness properties to resist low temperature shrinkage cracking at −22degrees Celsius. The lower the low temperature PG of liquid asphalt is,the greater resistance it will have to low temperature cracking.

The low temperature PG subtracted from the high temperature PG is theworking temperature range an asphalt will perform at. A PG 64-22, forexample, has a working temperature range of 86 degrees Celsius.Typically, liquid asphalt producers are limited to producing unmodifiedasphalt with a working temperature range of up to 92 degrees Celsius.Producers need to modify asphalt with a polymer to produce an asphaltwith a working range larger than 92.

The table below summarizes the PG test results that compared an asphaltblended with Kraton® D1101 (commercial SBS polymer) to the same asphaltbut blended with PS-PAESO-PS biopolymer

SBS (Kraton ®) blended with S-PAESO-S blended with unmodified asphaltunmodified asphalt Blended 3% Kraton ®D1101 Blended 3% S-PAESO-S toliquid asphalt with a high to liquid asphalt with a high temperature PGof 51.3 degrees temperature PG of 51.3 degrees Celsius increased itsCelsius increased its high temperature high temperature PG to 61.4degrees Celsius. PG to 62.1 degrees Celsius. Blended 3% Kraton ®D1101Blended 3% S-PAESO-S to liquid asphalt with a low to liquid asphalt witha low temperature PG of −36.3 degrees temperature PG of −36.3 degreesCelsius changed its Celsius changed its low temperature low temperaturePG to −34.1 degrees Celsius. PG to −33.1 degrees Celsius. Blended 3%Kraton ®D1101 Blended 3% S-PAESO-S to liquid asphalt increased to liquidasphalt increased its PG temperature range from its PG temperature rangefrom 87.6 to 95.5 degrees Celsius. 87.6 to 95.2 degrees Celsius.

Although preferred embodiments have been depicted and described indetail herein, it will be apparent to those skilled in the relevant artthat various modifications, additions, substitutions, and the like canbe made without departing from the spirit of the present invention andthese are therefore considered to be within the scope of the presentinvention as defined in the claims which follow.

What is claimed:
 1. A method of preparing a thermoplastic statisticalcopolymer, said method comprising: providing a radically polymerizablemonomer, represented by A; providing a radically polymerizabletriglyceride or mixture thereof, in the form of a plant oil, animal oil,or synthetic triglycerides, represented by B; and polymerizing monomer Aand monomer B simultaneously, via reversible addition-fragmentationchain-transfer polymerization (RAFT), in the presence of a free radicalinitiator and a chain transfer agent to form the thermoplasticstatistical copolymer, wherein said polymerizing is carried out underconditions effective to achieve a number average degree ofpolymerization (N_(n)) for the thermoplastic statistical copolymer of upto 100,000 without gelation.
 2. The method of claim 1 furthercomprising, prior to said polymerizing: providing a radicallypolymerizable monomer, represented by C, wherein monomer C is differentthan monomer A or monomer B, wherein said polymerizing comprisespolymerizing monomer A, monomer B, and monomer C simultaneously, viaRAFT, in the presence of the free radical initiator and the chaintransfer agent to form the thermoplastic statistical copolymer.
 3. Themethod of claim 1, wherein said polymerizing is carried out at a molarratio of the chain transfer agent to the monomer ranging from 1:1 to50:1.
 4. The method of claim 1 further comprising: catalyticallyhydrogenating reactive unsaturated sites in the thermoplasticstatistical copolymer to partial or full saturation after saidpolymerizing.
 5. The method of claim 1, wherein the monomer A and themonomer C, if present, are each independently vinyl, acrylic, diolefin,nitrile, dinitrile, acrylonitrile monomer, a monomer with reactivefunctionality, or a crosslinking monomer.
 6. The method of claim 5,wherein the monomer A and the monomer C, if present, are eachindependently selected from the group consisting of styrene, α-methylstyrene, t-butyl styrene, vinyl xylene, vinyl naphthalene, vinylpyridine, divinyl benzene, vinyl acetate, N-vinylpyrrolidone, methylacrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate, butyl (meth)acrylate, heptyl (meth)acrylate, hexyl(meth)acrylate, acrylonitrile, adiponitrile, methacrylonitrile,butadiene, isoprene, and mixtures thereof.
 7. The method of claim 6,wherein the monomer A and the monomer C, if present, are eachindependently styrene or methyl (meth)acrylate.
 8. The method of claim1, wherein the monomer B is a radically polymerizable plant oil monomerselected from the group consisting of soybean oil, corn oil, linseedoil, flax seed oil, and rapeseed oil.
 9. The method of claim 1, whereinthe triglyceride comprises one or more conjugated sites.
 10. The methodof claim 1, wherein the triglyceride is an acrylated epoxidizedtriglyceride.
 11. The method of claim 2, wherein the monomer C is aradically polymerizable triglyceride or mixture thereof, in the form ofa plant oil, animal oil, or synthetic triglycerides, wherein the monomerC is from a different plant oil or animal oil than the monomer B, or thetriglycerides of the monomer C have a different degree of conjugationthan the monomer B.
 12. The method of claim 1, wherein the monomer A isstyrene, the monomer B is soybean oil, and the monomer C, if present, isa linear chain-extending monomer.
 13. The method of claim 1, whereinsaid polymerizing is carried out at a temperature of 0 to 150° C. 14.The method of claim 1, wherein said polymerizing is carried out in asolvent at a temperature of 50 to 85° C.
 15. The method of claim 1,wherein said polymerizing is carried out in a solvent with the solventbeing toluene, THF, chloroform, cyclohexane, dioxane, dimethylsulfoxide, dimethyl formamide, acetone, acetonitrile, n-butanol,n-pentanol, chlorobenzene, dichloromethane, diethylether, tert-butanol,1,2,-dichloroethylene, diisopropylether, ethanol, ethylacetate,ethylmethylketone, heptane, hexane, isopropylalcohol, isoamylalcohol,methanol, pentane, n-propylacohol, pentachloroethane,1,1,2,2,-tetrachloroethane, 1,1,1,-trichloroethane, tetrachloroethylene,tetrachloromethane, trichloroethylene, water, xylene, benzene,nitromethane, or a mixture thereof.
 16. The method of claim 14, whereinsaid polymerizing is carried out in a solvent with the monomers beingdissolved in the solvent at a concentration ranging from 5% to 100 wt %.17. The method of claim 14, wherein said polymerizing is carried out ina solvent with the monomers being dissolved in the solvent at aconcentration ranging from 10% to 40 wt %.
 18. The method of claim 1,wherein the initiator is benzoyl peroxide or azobisisobutyronitrile. 19.The method of claim 1, wherein the chain transfer agent is athiocarbonylthio compound, a dithioester compound, a trithiocarbonatecompound, a dithiocarbamate compound, or a xantate compound capable ofreversible association with polymerizable free radicals.
 20. The methodof claim 1, wherein the chain transfer agent is 1-phenylethylbenzodithioate or 1-phenylethyl 2-phenylpropanedithioate.